Question

поможіть плиз треба ....​

Answer 1

$\int\limits^{ 3} _ {0} \frac{dx}{ \sqrt{9 - {x}^{2} } } = \int\limits^{ 3 } _ {0} \frac{dx}{ \sqrt{ {3}^{2} - {x}^{2} } } = arcsin( \frac{x}{3}) |^{ 3 } _ {0} = \\ = arcsin(1) - arcsin(0) = \frac{\pi}{2} - 0 = \frac{\pi}{2}$