Answer:
B) -3.464
Explanation:
∫₀³ g'(x) cos²(2g(x) + 1) dx
Using u substitution:
u = 2g(x) + 1
du = 2g'(x) dx
½ du = g'(x) dx
When x = 0, u = 11.
When x = 3, u = -3.
½ ∫₁₁⁻³ cos²(u) du
You can use a calculator to solve this, or you can evaluate algebraically.
Use power reduction formula:
½ ∫ (½ + ½ cos(2u)) du
¼ ∫ du + ¼ ∫ cos(2u) du
¼ ∫ du + ⅛ ∫ 2 cos(2u) du
¼ u + ⅛ sin(2u) + C
Evaluating from u = 11 to u = -3:
[¼ (-3) + ⅛ sin(-6) + C] − [¼ (11) + ⅛ sin(22) + C]
-⁷/₂ + ⅛ sin(-6) − ⅛ sin(22)
−3.464