$$ \int_\limits{-1}^1 \frac{d}{d x}\left(\tan ^{-1} \frac{1}{x}\right) d x \text { is } $$

$$\int\limits_{-\pi / 2}^{\pi / 2} \sin ^2 x d x$$ is equal to

$$ \int_0^2\left|x^2+2 x-3\right| d x \text { is equal to } $$

$$\int\limits_{ - {\pi \over 2}}^{{\pi \over 2}} {\cos x\,dx} $$