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Curves and Gradient
On Curves, every point has a different Gradient
Can you find a rule for getting the Gradient atany point on a Curve?
−4 −3 −2 −1 1 2 3 4 5
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The Derived FunctionConsider the curve y = f ( x ) (in red) and the gradient of the tangent
at P. Note that as h tends toward 0 the gradient of the line PQapproaches the gradient of the curve at P.
f ( x) =
0
lim
→h h
x f h x f )()( −+
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−4 −3 −2 −1 1 2 3 4 5
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For y = x2
Gradient for different x values
X at points -2 -1 0 1 2
gradient -4 -2 0 2 4
What is the Rule for finding gradient at different points (x)?
For y = x2
the Gradient Rule is y’ = 2x
So at the Point where x=1.5, the Gradient is..m = 2x1.5 = 3
−4 −3 −2 −1 1 2 3 4 5
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−8 −7 −6 −5 −4 −3 −2 −1 1 2 3 4 5 6 7 8
−7
−6
−5
−4
−3
−2
−1
1
2
3
4
5
6
7
y = x^3
At x = -1, Gradient = 3
−8 −7 −6 −5 −4 −3 −2 −1 1 2 3 4 5 6 7 8
−7
−6
−5
−4
−3
−2
−1
1
2
3
4
5
6
7
y = x^3
At x = -2, Gradient = 12
−8 −7 −6 −5 −4 −3 −2 −1 1 2 3 4 5 6 7 8
−7
−6
−5
−4
−3
−2
−1
1
2
3
4
5
6
7
y = x^3
At x = 1, Gradient = 3
−8 −7 −6 −5 −4 −3 −2 −1 1 2 3 4 5 6 7 8
−3
−2
−1
1
2
3
4
5
6
7
8
9
10
11
y = x^3
At x = 2, Gradient = 12
−8 −7 −6 −5 −4 −3 −2 −1 1 2 3 4 5 6 7 8
−6
−5
−4
−3
−2
−1
1
2
3
4
5
6
7
8
y = x^3
At x = 0 Gradient = 0
For Y = x 3
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For y = x3
Gradient for different x values
X at points -2 -1 0 1 2
gradient 12 3 0 3 12
What is the Rule for finding gradient at different points (x)?
For y = x3
the Gradient Rule is y’ = 3x2
So at the Point where x=1.5, the Gradient is 3x1.52
=7.75
−8 −7 −6 −5 −4 −3 −2 −1 1 2 3 4 5 6 7 8
−4
−3
−2
−1
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y = x^3
At x = 1.5 Gradient =7.75
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General Rule for getting the Gradient Formula
for ANY Curve’s Equation
For y = x2 y’ = 2x
For y = x3 y’ = 3x2
So to get any Gradient Formula
For a given Curve we use this rule…
Use the Curve’s equation…
“times by the Power & take 1 from the power”
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Differentiation rules
Finding the Gradient rule is called Differentiation
The Gradient rule is called dy/dx or y’ or f’(x)
We must write the Original Curve equation using Powers.
There are short cuts to get the y’ for some harder Curve Equations.
Note these types of equations & the short cut way to get its y’…
For Y = ( 3x - 4 )5……..Use “fn of a fn” or “ bracket rule”
For Y = 1 / (3x2 – 1) …use negative powers: y = (3x2 – 1 ) -5
For Y = 4x / ( 3x2 – 1 )… use the Quotient rule
For y = ( 3x2 – 1) ( 3x - 4 )5…… use the Product rule
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Equations of Tangents and Normals
Tangents are straight Lines which
touch Curves at a point of Contact .
Normals are straight lines that are perpendicular to tangents, passing
through the point of contact.
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−3.0 −2.0 −1.0 1.0 2.0 3.0 4.0A
B
C
Tangent & Normal
Tangent
Norma l
Point of contact
( x1 , y1 )
For Tangent’s Gradient
get Curve’s dy/dx, then sub
x1 into dy/dx
Normal
tangent
For Normal’s Gradient:
Get Tangent’s, then “flip
& change the Sign”
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y – 6.25 = 5 ( x – 2.5 )
Y = 5x - 6
Gradient at point of contact
Co ordinates of point of contact (x1 ,y1 )
Get dy / dx for the curve
Then substitute the x value
of the point of contactm
Y = x2
dy/dx = 2 x (use for
Gradient at x =2.5)
m = 2 x 2.5
m = 5
For x = 2.5
So y = x2
= 2.52
=6.25
y – y1 = m ( x – x 1 )
Tangent
equation
St. Line
equation
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B
#/2 = 1.2 # = 2.5
Tangent & Gradient
Tangent
Gradient Pt B has x value =
For x 1 = 2.5
So y1 = x2
= 2.52
=6.25
Y = x2
dy/dx = 2 x (use for
Gradient at x =2.5)
m = 2 x 2.5
m = 5
y – y1 = m ( x – x 1 )
y – 6.25 = 5 ( x – 2.5 )
Y = 5x - 6
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Equation of Normals
1. GET THE CURVE’S DY/DX
2. SUSTITUTE THE X-VALUE OF THECONTACT POINT. (this gets the tangent
gradient).
3. FLIP & CHANGE THE SIGN (this gets the
normal’s gradient, m ).
4. Use the formula y –y1 = m ( x – x 1 ) for
the normal’s equation.
( x1, y1 ) are the co ordinates of the point of contact
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Curves and Gradient2
Where is the Gradient = 0 ? ….For what x value(s)?
Where is the Gradient Positive? ….For what x value(s)?
Where is the Gradient Negative ? ….For what x value(s)?
The Gradient features of Curves….Positive Negative Zero
Help us to Describe Curves and to Draw them
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5.0
−15.0
−10.0
−5.0
5.0
10.0
15.0
y = x^3-12x
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5.0
−15.0
−10.0
−5.0
5.0
10.0
15.0
y = 12x - x^3
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5.0
−15.0
−10.0
−5.0
5.0
10.0
15.0
y = x^4 - 8x^2
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5.0
−15.0
−10.0
−5.0
5.0
10.0
15.0
y = 8x^2 - x^4
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5.0
y = (x - 4)^3
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5.0
y = (4 - x)^3
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5.0
10.0
y = x^4- 16/3*x^3 + 8x^2
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5.0
y = 8/3*x^3 - x^4
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5.0
y = x^4 + 2
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5.0
y = 5 - x^4
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Stationary Points
Where the Gradient is 0 “Stationary Points”..the curve “turns”
Either side of these Stationary Points (flat)….
the Gradient could be Positive (“Increasing”) or
Negative (“Decreasing”)
−4 −3 −2 −1 1 2 3 4 5
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4y = x^2
−4 −3 −2 −1 1 2 3 4 5
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4y = -x^2
−4 −3 −2 −1 1 2 3 4 5
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−3
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4 y = x^3
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Curve Sketching example.
Finding the Stationary Points
Curve Equation
Get dy/dx
1stDerivative
Solvedy/dx=0
Get thematching
Y-value(s)
F(x) F’(x) F’(x) = 0
X =..
Use f(x) ;substitute the xvalue(s) and get
the matching Y-values
This gets the Stationary Points for the curve …
“Flats” atthese x’s
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Curve Sketching example.
Finding the Stationary Points
Curve Equation
Get dy/dx
1stDerivative
Solvedy/dx=0
Get thematching
Y-value(s)
Y = X3 – 3x Y’ = 3x2 - 3 3x2 – 3 = 0
X2 = 1
X = +1 & -1
For X=1 get
>y=13-3x1=-2
For x=-1 get ..
Y=-13-3x-1=2
Stationary Points for the curve are… (1,-2) & (-1,2)
“Flats” at
these x’s
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−4 −2 2 4
−4
−2
2
4
(x,y) = (1,-2)
(x,y) = (-1,2)
Curve Sketching example.
Sketching using the Stationary Points
1.Plot Point (1.-2)
Turning point”max2.Plot Point (1.-2)
Turning point”min
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Curve Sketching example.
Sketching using the Stationary Points
−4 −2 2 4
−4
−2
2
4y = x^3 - 3x
(x,y) = (1,-2)
(x,y) = (-1,2)
2.Plot Point (1.-2)
Turning point”min
1.Plot Point (1.-2)
Turning point”max
3.Join the dots & fill in
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Concavity
Maximum, Minium or….?
3 types of turning points/ stationary points.
Minimum
Maximum
Horizontal inflexion
How do we find which type of stationary point we have?
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−4 −2 2 4
−4
−2
2
4
Concave UP a MINimum turning point at x= 0
Check the GRADIENT , Either Side of the Turning Point
-NegativeGradient- +PositiveGradient+
X value Left of 0 0 Right of 0
Gradient negative zero positive
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−4 −3 −2 −1 1 2 3 4 5
−4
−3
−2
−1
1
2
3
4y = -x^2Concave DOWN a MAXimum turning point at x=0
Check the GRADIENT , Either Side of the Turning Point
X value Left of 0 0 Right of 0
Gradient positive zero negative
-Negative
Gradient-+Positive
Gradient+
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−4 −3 −2 −1 1 2 3 4 5
−4
−3
−2
−1
1
2
3
4 y = x^3
½ MIN JOINED TO ½ MAX
HORIZONTAL INFLEXION
Flat Point at x = 0
-Negative
Gradient-
-Negative
Gradient-
Check the GRADIENT , Either Side of this Turning Point
X value Left of 0 0 Right of 0
Gradient negative zero negative
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Types of Turning Points
How to determine the Nature of Stationary points
1. Solve dy/dx = 0 to get the x values of the stationary
points
2. Check the SIGN of the Gradient either side of each x
value ( Positive? Negative? ). Thus see if
3. Min ..concave UP4. Max .. concave DOWN
5. Horizontal Inflexion… SAME gradient left & right
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X value Left of SP SP X Right of SP
Gradient ? zero ?
Concave DOWN a MAXimum turning point at x=0
Concave UP a MINimum turning point at x= 0
Horizontal Inflexion..½ MIN JOINED TO ½ MAX
Neg zero Pos
Neg zero Neg Pos zero Pos
Pos zero Neg
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Repeated Differentiation,
Concavity & the 2nd derivative
Y = x2
Y’ = 2x
Y” = 2 ( positive)
−4 −2 2 4
−4
−2
2
4
Concave UP
BOTH “CONCAVE UP” & “CONCAVE DOWN”.
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BOTH CONCAVE UP & CONCAVE DOWN .
WHERE DOES CONCAVITY CHANGE ?
−4 −3 −2 −1 0 1 2 3 4 5−2 0
−1 5
−1 0
−5
0
5
10
15
M=0
M=-9
M=-11
M=-12
M=-11
M=-9
M=0
Y=12x-x3
Y’=12-3x2
Y”= -6x
Where is Gradient the Greatest,
between the 2
turning points?
The concavity changes at some point between the 2 turning points.
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Y = x2
Y’ = 2x
Y” = 2 ( positive)−4 −2 2 4
−4
−2
2
4
Concave UP
Y = -x2
Y’ = -2x
Y” = -2 (negative) Concave DOWN
−4 −3 −2 −1 1 2 3 4 5
−4
−3
−2
−1
1
2
3
4y = -x^2
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Y=12x-x3
Y’=12-3x2
Y”= -6x
Y” values at
Pts. ..2nd
derivative values
shown.
Y”=12
Y”=6
Y”=3
Y”=0
Y”=-3
Y”=-6
Y”=-12
The Sign of Y” value at a point indicates the Concavity at that point.
Positive+ Y” C.UP …. Negative- Y” C.DOWN
The Sign of the Y” value at a Point, and the Concavity at that point.
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−4 −3 −2 −1 0 1 2 3 4 5−2 0
−1 5
−1 0
−5
0
5
10
15
Y”=0 for the x-value at
this point ( x= -1.2)
Y”=0 for the x-value
at this point ( x=1.2)
Y=8x^2-x^4
Inflexion points & 2nd Derivative (y”)
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−4 −3 −2 −1 0 1 2 3 4 5−2 0
−1 5
−1 0
−5
0
5
10
15
Where does Concavity change?
2 types of Inflexion Points
Y”=0 for the x-value
(x=1.3) at this point
Y”=0 for the x-value(x=0)
at this point…AND also
y’=0 for the x-value here.
This point (x=0) isa Horizontal
Inflexion point
Y=8x^3-3x^4
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2 types of Inflexion Points
“ordinary” InflexionPoint
“Horizontal
Inflexion Point
“Visible” pt.
y”=0 AND
y’=0
“Not Visible”..
y”=0
Finding Inflexion Points Where the change in Concavity occurs
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Finding Inflexion Points..Where the change in Concavity occurs
Solve Y” = 0 x-values of possible Inflexions (both types)
Y = f(x) y’ = f’(x) y” = f”(x)
Solve
f’(x) = 0
stat.point
x -values
Solve f”(x)
= 0 possible
InflexionPt
x -values
Test if
genuine:
Check y”
changes+/-
Get the
y-values
using
y=f(x)
Get the
y-values
using
y=f(x)
Test if
Concave UP
or Down, or
Horz Inflxn:
Stationary
points
Inflexion
points
30
yOriginal
Moving tangent to a cubic
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-20
-15
-10
-5
0
5
10
15
20
25
-5 -4 -3 -2 -1 0 1 2 3 4 5
x
y functionMoving tangent to a cubicPress the spinners to change the coefficients.
y = 1 x³ – 3 x² + 3 x + 5
ngent at x = 1.0
Function is y = 1x³ – 3x² + 3x + 5
At x = 1.0 , the gradient is 0.00
at x = 1.0 , the value of Y" is 0
T
Y=x3-3x2+3x+5
Y’=3x2-6x+3
Y”=6x-6
Stationary Pts :Y’ = 0 x = 1
Inflexion Pts : Y” = 0 x =1
25
30
y Original
functiony = 1 x³ – 3 x² – 6 x + 5
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-20
-15
-10
-5
0
5
10
15
20
25
-5 -4 -3 -2 -1 0 1 2 3 4 5
x
y
ngent at x = 1.0
Function is y = 1x³ – 3x² – 6x + 5
At x = 1.0 , the gradient is -9.00
at x = 1.0 , the value of Y" is 0
T
Y=x3-3x2-6x+5
Y’=3x2-6x-6
Y”=6x-6
Stationary Pts :Y’ = 0 x = -0.8 & x = 2.7
Inflexion Pts : Y” = 0 x =1
Concave UP x>1 & Concave DOWN x<1
3
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−2 −1 1 2 3
−2
−1
1
2
Y = x4 – x2
Y’ = 4x3 – 2x
y’” = 12x2-2
Stationary Pts :Y’ = 0 x = 0 & x = 0.7 & x = -0.7
Inflexion Pts : Y” = 0 x =0.4 & x= -0.4
Concave UP : x<-0.4 & x>0.4 Concave Down –0.4,x,0.4
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−5 5 10
−5
5
B
6-3## = 6.00
-6# = 0.00
Gradient =
Y" value =
Gradient & Y" values at Points on the Curve.
Anim>use # slider
y=6x-x^3
Concave up
Y” positive
Concave down
Y” negative
Inflexion pt..
Y” = 0, for this
point’s x value
C
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−5 5
−5
5
B
y=6x-x^3
Decreasing
X<-1.4
Decreasing
X>1.4
Increasing-
1.4<x<1.4
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INCREASING/ DECREASING ?
CONCAVE UP / CONCAVE DOWN ?
X values where fn has positive Gradient increasing
X values where fn has negative Gradient decreasing
You need the stationary points
X values where fn is concave Up… y” is Positive
X values where fn is concave Down… y” is Negative
You need the point(s) of Inflexion
G phs f R l Lif Sit ti ns (2)
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Discuss what happens to p as q increases in each of the graphs below,
then match each graph to a statement on the right.
p increases quickly at
first, then more slowly
1 2
3
q q
q
p p
p
4 q
p
p increases slowly at
first, then more quickly
p increases slowly at
first, then more quickly
then slowly again
p increases quickly at
first, then more slowly,
then quickly again
2
1
4
3
Graphs of Real-Life Situations (2)
Graphs of Real Life Situations (4)
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Population
P o p u l a t i o n
1955 2005
The graphs below show how the population of four small African countries
changed over a 50 year period. Match each graph to a statement.
P o p u l a t i o n
1955 2005
P o p u l a t i o n
1955 2005
P o p u l a t i o n
1955 2005
The population
declined steadily over
the period.
The population
increased slowly at
first, but then increasedmore quickly.
The population
increased steadily over
the period.
The population
increased quickly at
first, but then increased
more slowly.
1 2
3 4
Graphs of Real-Life Situations (4)
Water is poured into each of the containers below at a
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Water 11 2 3 4
dd d
t t
d
tt
Water is poured into each of the containers below at a
constant rate of 250 ml per second. The graphs show
how the depth d of the water varies with time t. Match
the container to its corresponding graph.
A B C D
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Graph of 1st Derivative Y’
from the Original Function graph Y
Can you see connections between a function’s Graph
and the graph of its Derivative?
A Function’s Derivative Graph shows the
ORIGINAL-Graph’s Gradient Values
Can you tell the Original Graph’s Gradient-features from
its Gradient f” Graph, & hence do a sketch of f(x)?
a b c d e f from to y on 1
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0 0 0 1 0 0 -4 4 y' on 1
x 5
x 4
x 3
x 2
x c
Function Derivative
-2
0
2
4
6
8
1 0
1 2
1 4
1 6
1 8
-6 -4 -2 0 2 4 6
-1 0
-8
-6
-4
-2
0
2
4
6
8
10
-6 -4 -2 0 2 4 6
Gradient values
Where is the Gradient Zero? Positive? Negative?
a b c d e f from to y on 1
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0 0 1 1 0 0 -4 4 y' on 1
x 5
x 4
x 3
x 2
x c
Function Derivative
-6 0
-4 0
-2 0
0
2 0
4 0
6 0
8 0
1 0 0
-6 -4 -2 0 2 4 6
-1 0
0
10
20
30
40
50
60
-6 -4 -2 0 2 4 6
Gradient values
Where is the Gradient Zero? Positive? Negative?
a b c d e f from to y on 1
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y
0 1 -4.5 -2.5 0 0 -4 6.1 y' on 1
x 5
x 4
x 3
x 2
x c
Function Derivative
-200
-100
0
100
200
300
400
500
600
-6 -4 -2 0 2 4 6 8
-500
-400
-300
-200
-100
0
100
200
300
400
500
-6 -4 -2 0 2 4 6 8
Gradient values
Where is the Gradient Zero? Positive? Negative?
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Max Min Problems
Calculus finds Min/Max points on curves from their equations.
We use the same ideas to solve these Practical Problems.
We can find the Maximum Area possible for a box, (with specified
volume & shape restrictions) form the various boxes that fit these
specifications.
We need a formula to differentiate for the Max (or Min)
property required (such as Area). This is based on given a
variable of the given shape (such as length of its base).
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A Stone is thrown
into the Air
The Height of the Stone
at different times is given
by this formula:
H = 4 + 3t - t 2
Find the Time when the Maximum height occurs using Calculus.
The actual Maximum Height.
Confirm it is a Max using Calculus.
−6 −4 −2 2 4 6
−4
−2
2
4
6y = 4 + 3x - x^2
For Time from T = 0 to when it hits the ground (t=4)
For t = 1.5 --> h = 6.25
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A Stone is thrown
into the Air
The Height of the Stone
at different times is given
by this formula:
H = 4 + 3t - t 2
Maximum height occurs when dh/dt =0 0 =3 – 2t t =1.5
Maximum Height? ..When t =1.5 , h = 4 + 3 x 1.5 – 1.52 So h=6.25
It is a Max since h” is Negative when t = 1.5. Thus Max when t = 1.5..
−6 −4 −2 2 4 6
−4
−2
2
4
6y = 4 + 3x - x^2
For Time from T = 0 to when it hits the ground (t=4)
For t = 1.5 --> h = 6.25
Y k B i h V l f 240 2
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You want to make a Box with a Volume of 240 m2
Using the LEAST amount of Cardboard
What is the formula for the Surface Area of this Box?
The Box must be a Rectangular
Prism with a Square base
What is the Formula for
the Volume of this Box?
A = 2x 2 + 4xh
V = x 2 x h
So 240 = x 2 x h
x
x
h
Using Calculus to solve Maximum / Minimum Problems
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Box Area (Volume=240, x is square base side) A= 2x 2 + 960/x
How do you get this Area equation? Use the 2nd equationto eliminate the unwanted variable
from the main equation
How does Calculus get
the Minimum Area?
A= 2x 2 + 960/x
dA/dx =4x – 960/x 2
Solve 0 = 4x –960/x 2
X = 6.2
A = 2x 2 + 4x h
A = 2x 2 + 4x( 240/x 2 )
1 2 3 4 5 6 7 8
10 0
20 0
30 0
40 0
50 0
60 0
70 0
80 0
90 0
y = 2xx + (960/x)
T he S qu are
4 A r e a v C i r c l e P
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and Circle problem 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2
1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2
1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2
1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2
1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2
1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2
1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2
1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2
1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2
1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2
1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2
1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2
1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2
1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2
1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2
1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2
1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2
1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2
1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2
1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2
1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2
1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2
1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2
1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2
1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2 1 9 2 2
- 4
- 3
- 2
- 1
0
1
2
3
- 4 - 3 - 2 - 1 0 1 2 3 4
0
5
1 0
1 5
2 0
2 5
3 0
3 5
0 1 0 2 0 3 0
L e n g t h o f c i rc le
T o t a l A r e a o f S q u a r e
a n d C i r c l e
A 2 0 c m st r i n g i s c u t i
p i e c e s. T h e f i rst p i e c esh a p e d i n t o a c i rc l e a
se c o n d i n to a s q u a r e .
W h e r e w a s th e s tr i n g
i s fo u n d t h a t th e t o ta l
th e s q u a r e a n d c i r c l e
b e e n m i n im i se d ?