integral

For the integral $I = \int_{-1}^{1} \frac{1}{x^2} dx$, which of the following statements is TRUE?

Let x be a continuous variable defined over the interval (-∞, ∞), and f (x) = e^-x - e^-x. The integral g(x) = ∫ f(x) dx is equal to

The value of the integral $\int_0^\pi x \cos^2x \,dx$ is