why do we need integration?nature-lover.net/math/c/oldcourse/f18/calculus1files/...(end of movie)...
TRANSCRIPT
![Page 1: WHY DO WE NEED INTEGRATION?nature-lover.net/math/c/oldcourse/f18/calculus1files/...(END OF MOVIE) X=0 TO X=1 WE HAVE (1^3/3)-(0^3/3) = 1/3 = 0.33 (APPROX) BY USING BLOCKS WE GOT AREA](https://reader033.vdocument.in/reader033/viewer/2022050315/5f774be64f3c7400f32b8dc3/html5/thumbnails/1.jpg)
WHY DO WE NEED
INTEGRATION?
![Page 2: WHY DO WE NEED INTEGRATION?nature-lover.net/math/c/oldcourse/f18/calculus1files/...(END OF MOVIE) X=0 TO X=1 WE HAVE (1^3/3)-(0^3/3) = 1/3 = 0.33 (APPROX) BY USING BLOCKS WE GOT AREA](https://reader033.vdocument.in/reader033/viewer/2022050315/5f774be64f3c7400f32b8dc3/html5/thumbnails/2.jpg)
INTEGRATION
1.FIGURE OUT FUNCTION FROM ITS RATE OF CHANGE 2. ADD VALUES OF A FUNCTION, ESPECIALLY INFINITELY MANY
![Page 3: WHY DO WE NEED INTEGRATION?nature-lover.net/math/c/oldcourse/f18/calculus1files/...(END OF MOVIE) X=0 TO X=1 WE HAVE (1^3/3)-(0^3/3) = 1/3 = 0.33 (APPROX) BY USING BLOCKS WE GOT AREA](https://reader033.vdocument.in/reader033/viewer/2022050315/5f774be64f3c7400f32b8dc3/html5/thumbnails/3.jpg)
SLOPE FIELD SHOWING RATE OF CHANGE
Each little arrow represents direction and size (usually by its length) of slope of a function at that point This is actually slope field of a bunch of curves, each the graph of a function
![Page 4: WHY DO WE NEED INTEGRATION?nature-lover.net/math/c/oldcourse/f18/calculus1files/...(END OF MOVIE) X=0 TO X=1 WE HAVE (1^3/3)-(0^3/3) = 1/3 = 0.33 (APPROX) BY USING BLOCKS WE GOT AREA](https://reader033.vdocument.in/reader033/viewer/2022050315/5f774be64f3c7400f32b8dc3/html5/thumbnails/4.jpg)
Examples
Velocity at a point V(t) = S’(t) where S(t) is position at time t Could try to figure out S(t) using V(t)
P’(t) = Growth of population in one year (very approximately) Knowing P’(t) for several years in a row, could try to figure out P(t) Similarly for revenue function, etc
![Page 5: WHY DO WE NEED INTEGRATION?nature-lover.net/math/c/oldcourse/f18/calculus1files/...(END OF MOVIE) X=0 TO X=1 WE HAVE (1^3/3)-(0^3/3) = 1/3 = 0.33 (APPROX) BY USING BLOCKS WE GOT AREA](https://reader033.vdocument.in/reader033/viewer/2022050315/5f774be64f3c7400f32b8dc3/html5/thumbnails/5.jpg)
INTEGRAL OF Y = X^2
LET US SAY THE SLOPE OF A CURVE F(X) IS GIVEN BY X^2 FOR ALL VALUES OF A FUNCTION SO F’(X) = X^2
THEN JUST BY GUESSING WE SEE THAT F(X) = X^3/3. (DERIVATIVE OF X^3/3 = 3X^2/3
= X^2)
![Page 6: WHY DO WE NEED INTEGRATION?nature-lover.net/math/c/oldcourse/f18/calculus1files/...(END OF MOVIE) X=0 TO X=1 WE HAVE (1^3/3)-(0^3/3) = 1/3 = 0.33 (APPROX) BY USING BLOCKS WE GOT AREA](https://reader033.vdocument.in/reader033/viewer/2022050315/5f774be64f3c7400f32b8dc3/html5/thumbnails/6.jpg)
ADDING VALUES OF A FUNCTION
![Page 7: WHY DO WE NEED INTEGRATION?nature-lover.net/math/c/oldcourse/f18/calculus1files/...(END OF MOVIE) X=0 TO X=1 WE HAVE (1^3/3)-(0^3/3) = 1/3 = 0.33 (APPROX) BY USING BLOCKS WE GOT AREA](https://reader033.vdocument.in/reader033/viewer/2022050315/5f774be64f3c7400f32b8dc3/html5/thumbnails/7.jpg)
PARABOLA Y = X^2
THIS SHOWS GRAPH FOR X =0 TO X=1 INFINITE NUMBER OF X-VALUES FROM 0 TO 1 WANT TO ADD Y-VALUES (OR FIND AREA UNDER CURVE)
![Page 8: WHY DO WE NEED INTEGRATION?nature-lover.net/math/c/oldcourse/f18/calculus1files/...(END OF MOVIE) X=0 TO X=1 WE HAVE (1^3/3)-(0^3/3) = 1/3 = 0.33 (APPROX) BY USING BLOCKS WE GOT AREA](https://reader033.vdocument.in/reader033/viewer/2022050315/5f774be64f3c7400f32b8dc3/html5/thumbnails/8.jpg)
IDEA: CHOP AREA INTO BLOCKS
AREA UNDER CURVE APPROXIMATED BY AREA OF BLOCKS
AREA OF UPPER BLOCKS = (.5)(.25) +(.5)1 = .625 AREA OF LOWER BLOCKS = .25(.5) = .125 ACTUAL AREA = .33
![Page 9: WHY DO WE NEED INTEGRATION?nature-lover.net/math/c/oldcourse/f18/calculus1files/...(END OF MOVIE) X=0 TO X=1 WE HAVE (1^3/3)-(0^3/3) = 1/3 = 0.33 (APPROX) BY USING BLOCKS WE GOT AREA](https://reader033.vdocument.in/reader033/viewer/2022050315/5f774be64f3c7400f32b8dc3/html5/thumbnails/9.jpg)
CHOPPING INTO MORE BLOCKS
NOW WE CHOP AREA INTO FOUR BLOCKS, EACH OF LENGTH .25
TOTAL AREA OF UPPER (.25)(.0625+.25+.5625+1) =0.46875 = 0.47 APPROX TOTAL AREA OF LOWER (.25)(.0625+.25+.5625) =0.21875 = 0.22 APPROX GETTING CLOSER!
![Page 10: WHY DO WE NEED INTEGRATION?nature-lover.net/math/c/oldcourse/f18/calculus1files/...(END OF MOVIE) X=0 TO X=1 WE HAVE (1^3/3)-(0^3/3) = 1/3 = 0.33 (APPROX) BY USING BLOCKS WE GOT AREA](https://reader033.vdocument.in/reader033/viewer/2022050315/5f774be64f3c7400f32b8dc3/html5/thumbnails/10.jpg)
CHOPPING EVEN FINER
AREA OF UPPER BLOCKS (EACH OF LENGTH 0.125) = 0.40 APPROX AREA OF LOWER BLOCKS = 0.27 APPROX ACTUAL AREA = 0.33 -- EVEN CLOSER!
![Page 11: WHY DO WE NEED INTEGRATION?nature-lover.net/math/c/oldcourse/f18/calculus1files/...(END OF MOVIE) X=0 TO X=1 WE HAVE (1^3/3)-(0^3/3) = 1/3 = 0.33 (APPROX) BY USING BLOCKS WE GOT AREA](https://reader033.vdocument.in/reader033/viewer/2022050315/5f774be64f3c7400f32b8dc3/html5/thumbnails/11.jpg)
AND EVEN FINER…!
AREA OF UPPER = 0.37 APPROX AREA OF LOWER =0.30 APPROX ACTUAL AREA = 0.33 -- ALMOST THERE!
![Page 12: WHY DO WE NEED INTEGRATION?nature-lover.net/math/c/oldcourse/f18/calculus1files/...(END OF MOVIE) X=0 TO X=1 WE HAVE (1^3/3)-(0^3/3) = 1/3 = 0.33 (APPROX) BY USING BLOCKS WE GOT AREA](https://reader033.vdocument.in/reader033/viewer/2022050315/5f774be64f3c7400f32b8dc3/html5/thumbnails/12.jpg)
MAKING IT EXACT
AS YOU CHOP INTO MORE AND MORE BLOCKS THE AREA OF BLOCKS GETS CLOSER AND CLOSER TO ACTUAL AREA
![Page 13: WHY DO WE NEED INTEGRATION?nature-lover.net/math/c/oldcourse/f18/calculus1files/...(END OF MOVIE) X=0 TO X=1 WE HAVE (1^3/3)-(0^3/3) = 1/3 = 0.33 (APPROX) BY USING BLOCKS WE GOT AREA](https://reader033.vdocument.in/reader033/viewer/2022050315/5f774be64f3c7400f32b8dc3/html5/thumbnails/13.jpg)
MAKING IT EXACT
HOW DO YOU MAKE IT EXACT?
![Page 14: WHY DO WE NEED INTEGRATION?nature-lover.net/math/c/oldcourse/f18/calculus1files/...(END OF MOVIE) X=0 TO X=1 WE HAVE (1^3/3)-(0^3/3) = 1/3 = 0.33 (APPROX) BY USING BLOCKS WE GOT AREA](https://reader033.vdocument.in/reader033/viewer/2022050315/5f774be64f3c7400f32b8dc3/html5/thumbnails/14.jpg)
ANSWER: TAKE LIMITS!
AREA = LIMIT OF SUM OF AREA OF BLOCKS, AS N GOES TO INFINITY N BEING NUMBER OF BLOCKS
![Page 15: WHY DO WE NEED INTEGRATION?nature-lover.net/math/c/oldcourse/f18/calculus1files/...(END OF MOVIE) X=0 TO X=1 WE HAVE (1^3/3)-(0^3/3) = 1/3 = 0.33 (APPROX) BY USING BLOCKS WE GOT AREA](https://reader033.vdocument.in/reader033/viewer/2022050315/5f774be64f3c7400f32b8dc3/html5/thumbnails/15.jpg)
NOW FOR THE PUNCHLINE
WHAT IS THE RELATION BETWEEN AREA UNDER Y = X^2 OBTAINED USING BLOCKS AND INTEGRAL OF X^2 = X^3/3 (BECAUSE (X^3/3)’ = X^2)
![Page 16: WHY DO WE NEED INTEGRATION?nature-lover.net/math/c/oldcourse/f18/calculus1files/...(END OF MOVIE) X=0 TO X=1 WE HAVE (1^3/3)-(0^3/3) = 1/3 = 0.33 (APPROX) BY USING BLOCKS WE GOT AREA](https://reader033.vdocument.in/reader033/viewer/2022050315/5f774be64f3c7400f32b8dc3/html5/thumbnails/16.jpg)
GRAND CONCLUSION (END OF MOVIE)
X=0 TO X=1 WE HAVE (1^3/3)-(0^3/3) = 1/3 = 0.33 (APPROX) BY USING BLOCKS WE GOT AREA = 0.33 (APPROX) SO THEY ARE THE SAME! THIS IS CALLED FUNDAMENTAL THEOREM OF CALCULUS