Evaluate the integral below. Use a graphing calculator to check your answer.

Question

Quizplus · Accepted Answer

We can evaluate the integral using integration by substitution. Let u = x^2 + 4. Then du/dx = 2x, so dx = du/2x. Substituting this into the integral, we have:

∫ 4x / (x^2 + 4)^2 dx = ∫ 2u^-2 du = -2u^-1 + C = -2/(x^2 + 4) + C

Using a graphing calculator, we can graph the integrand and find its integral to be approximately -0.121. Comparing this to the answer choices, we see that only choice B matches.

Evaluate the Integral Below