Let me give you a simple idea. The first question is typical. If the root sign is not the derivative of the inverse trigonometric function, we should use the method of trigonometric substitution, y = 2√2 sinx, and then integrate after substitution, paying attention to changing the upper and lower limits of integration.

In fact, the second question does not need to be calculated, and the formula can be set directly, that is, when the upper and lower limits of the integral are 0, π/2, if the integral of the integer power of sinx and cosx is odd, it is equal to (n- 1)! ! / (n)！ ! (Two exclamation points indicate multiplication of every other item, such as 5! ! It means 5*3* 1), and if it is even, it is equal to (n- 1)! ! / (n)！ ! * π/2。 This formula can be deduced by mathematical induction.