Understanding the Fundamental Theorem of Calculus and its Applications

1. Sec4-4: (Day1) Fundamental Theorem of Calculus Sec4-4: #2-38 evens Fundamental Theorem of Calculus: Makes a connection between Indefinite Integrals (Antiderivatives) and Definite Integrals (“Area”) Historically, indefinite integrationhas always been defined to be the inverse of differentiation. is the collection of all possible anti-derivatives of f(x), which happen to differ only by a constant. But definite integration, motivated by the problem of finding areas under curves, was originally defined as a limit of Riemann sums. Is the limit of any Riemann sum as the number of rectangles approaches infinity … provided the limit of the Lower and the limit of the Upper Riemann sums are equal.

2. Only later was it discovered that the limits of these Riemann sums can actually be computed with antiderivatives, leading to our modern Fundamental Theorem of Calculus. _________________ _______________________________ The fundamental theorem allows us to calculate definite integrals By using anti-derivatives (indefinite integrals) _________________

3. Proof of The Fundamental Theorem of Calculus (1) Write down the definition of the definite integral. (2) Write down the definition of the indefinite integral.

4. The Fundamental Theorem of Calculus Mean Value Theorem: If (1) g is a continuous on a/an __________________ interval (2) g is differentiable on a/an __________________ interval. Then, there is a mean value, x = c, in the open interval (a,b) such that (3) How can you be sure that the mean value theorem applies to the function

5. Exploration 5-6b: The Fundamental Theorem of Calculus (4) The figure shows function g in problem 2. Write the conclusion f the mean value theorem as it applies to g on the interval from x = a to x = x1, and illustrate the conclusion on the graph.

6. Exploration 5-6b: The Fundamental Theorem of Calculus (4) The figure shows function g in problem 2. Write the conclusion f the mean value theorem as it applies to g on the interval from x = a to x = x1, and illustrate the conclusion on the graph. Slope of tangent line = slope of secant line

7. The Fundamental Theorem of Calculus (5) The figure shows function f (x) from Problem 2. Let c1, c2, c3, …, cn be the sample points determined by the mean value theorem as in problem 4. Write a Riemann sum Rn for Use these sample points and equal Dx values. Show the Reimann sum on the graph.

8. Exploration 5-6b: The Fundamental Theorem of Calculus (5) Write a Riemann sum Rn for

9. Exploration 5-6b: The Fundamental Theorem of Calculus On a separate sheet of paper, write down what is on this page and fill in the blanks By the mean value theorem: By the definition of indefinite integrals, Slope of tangent = Slope of Secant g is an anti-derivative of f if g’(x)=f (x)

10. The Fundamental Theorem of Calculus (6) By the mean value theorem: By the definition of indefinite integrals, By appropriate substitutions, show that Rn from problem 5 is equal to: Make a substitution into the Riemann sum we wrote in problem 5.

11. The Fundamental Theorem of Calculus (6) By appropriate substitutions, show that Rn from problem 5 is equal to: Make a substitution into the Riemann sum we wrote in problem 5.

12. Rewrite the reimann sum from the previous page cancel the Dx Rearrange the terms so you can see what will cancel Cancel everything that will cancel to get …

13. The Fundamental Theorem of Calculus (7) Rn from Problem 6 is independent of n, the number of increments. Use this fact, and the fact that Ln < Rn < Un to prove that the fundamental theorem of calculus: Since Ln< Rn< Un Since Rn=g(b)-g(a)

14. The Fundamental Theorem of Calculus (8) The conclusion in Problem 7 is called the fundamental theorem of calculus. Show that you understand what it says by using it to find the exact value of: Fundamental Theorem of Calculus Provide that g is an antiderivative of f 1st Find g(x), an antiderivative of f 2nd Evaluateg(x) at a=1 and at b=4 3rd Subtract to get the exact value:

15. The Fundamental Theorem of Calculus (8) Show that you understand what it says by using it to find the exact value of: Fundamental Theorem of Calculus Provide that g is an antiderivative of f