Expand each of the following integrals. That is, write each one as a sum of constant multiples of the integrals of the powers of the variables.
- [a [math]\int_0^1 (x^2 + 5x) \; dx[/math]
- [math]\int_2^3 (4x^5 - x - 2) \; dx[/math]
- [math]\int_1^2 (3t^2 + 2t^2 + t) \; dt[/math]
- [math]\int_5^3 (17y^{13} - 11y^7 + 4) \; dy[/math]
- [math]\int_0^1 (x^2 + 2)^2 \; dx[/math].
Given that [math]\int_0^1 x^n \; dx = \frac1{n+1}[/math], for every nonnegative integer [math]n[/math], evaluate
- [math]\int_0^1 (2x^2 + 3x) \; dx[/math]
- [math]\int_0^1 (5x^3 - x^2 - 2) \; dx[/math]
- [math]\int_0^1 (3t^2 - 1) \; dt[/math]
- [math]\int_0^1 (x + 2)^2 \; dx[/math]
- [math]\int_0^1 (3y^2 - y + 1) \; dy[/math].
Use the result
and the analogous result at the beginning of Problem Exercise to evaluate
- [math]\int_1^2 (3x^2 - 2x + 1) \; dx[/math]
- [math]\int_0^2 x^2 \; dx[/math]
- [math]\int_0^2 (4x^3 - 3x + 2) \; dx[/math]
- [math]\int_0^2 (t^3 + t^2 + t) \; dt[/math].
Using the definition of integrability, prove Theorem \ref{thm 4.4.4}. (Suggestion: Treat the cases [math]k \geq 0[/math] and [math]k \leq 0[/math] separately.)
Using \ref{thm 4.4.3}, prove that if [math]f[/math] and [math]g[/math] are integrable over [math][a,b][/math] and if [math]f(x) = g(x)[/math], for every [math]x[/math] in [math][a,b][/math], then
Prove that if [math]f[/math] is integrable over [math][a,b][/math] and if [math]f(x) \leq M[/math] for all [math]x[/math] in [math][a,b][/math], then
Replace the symbol [math]*[/math] by either [math]\leq[/math] or [math]\geq[/math] so that the resulting expressions are correct. Give your reasons.
- [math]\int_0^1 x^2 \; dx * \int_0^1 x^3 \; dx[/math]
- [math]\int_{-1}^1 x^2 \; dx * \int_{-1}^1 x^3 \; dx[/math]
- [math]\int_1^3 x^2 \; dx * \int_1^3 x^3 \; dx[/math].
Plot the graph of the function [math]f(x) = 1 - x^2[/math], and indicate the region [math]P^+[/math] defined by the inequalities [math]0 \leq x \leq 2[/math] and [math]0 \leq y \leq f(x)[/math] and the region [math]P^-[/math] defined by the inequalitiy [math]0 \leq x \leq 2[/math] and [math]f(x) \leq y \leq 0[/math].
- Use the identities given in Problems {4.4.2} and {4.4.3} to evaluate the integrals [math]\int_0^1 f(x) \; dx[/math], [math]\int_1^2 f(x) \; dx[/math], and [math]\int_0^2 f(x) \; dx[/math].
- Find [math]\mathit{area}(P^+)[/math], [math]\mathit{area}(P^-)[/math], and [math]\mathit{area}(P^+ \cup P^-)[/math].
Draw the graph of the function [math]f(x) = x(x-2)(x-4) = x^3 - 6x^2 + 8x[/math], and indicate the region [math]P^+[/math] defined by the inequalities [math]0 \leq x \leq 3[/math] and [math]0 \leq y \leq f(x)[/math], and the region [math]P^-[/math] defined by [math]0 \leq x \leq 3[/math] and [math]f(x) \leq y \leq 0[/math]. Let [math]P = P^+ \cup P^-[/math], and suppose that [math]\int_0^2 f(x) \; dx = 4[/math] and [math]\int_0^3 f(x) \; dx = 2\frac14[/math]. Find [math]\mathit{area}(P^+)[/math], [math]\mathit{area}(P^-)[/math], and [math]\mathit{area}(P)[/math].
Prove case \ref{thm 4.4.7}(iii) of Theorem \ref{thm 4.4.7}.