Calculus / Unit 8: The Fundamental Theorem of Calculus
8.2 Evaluating Integrals of Polynomials, Trig and Exponentials
Notes
Use the basic antiderivative rules, then apply FTC Part 2.
- Example: $\displaystyle \int_0^2 (3x^2 - 2x + 1)\,dx = \left[x^3 - x^2 + x\right]_0^2 = (8 - 4 + 2) - 0 = 6$.
- $\displaystyle \int_0^\pi \sin x\,dx = \left[-\cos x\right]_0^\pi = 1 + 1 = 2$.
- $\displaystyle \int_0^1 e^x\,dx = e - 1$ and $\displaystyle \int_1^e \frac{1}{x}\,dx = \ln e - \ln 1 = 1$.
Practice
Find $\displaystyle \int_0^2 (3x^2 - 2x + 1)\,dx$.
$[x^3 - x^2 + x]_0^2 = 8 - 4 + 2 = 6$.
Find $\displaystyle \int_0^\pi \sin x\,dx$.
$[-\cos x]_0^\pi = -(-1) - (-1) = 2$.
Find $\displaystyle \int_1^e \frac{1}{x}\,dx$.
$[\ln x]_1^e = 1 - 0 = 1$.
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