For high school students, due to the limitation of integral learning scope, such topics will not be tested. The integrand function is sin at most. X, cosX, correlation integral, and circle, plus some other irregular functions at most, but the area is easy to get after painting.

For high school students, I just want to test you. An integral is the area.

Therefore, whenever we encounter this kind of problem, we should move closer to the graph of the center of the circle and the trigonometric function and simplify the part of the simple product function. Within the radical sign, it is obviously formulaic, and trigonometry can be used instead, and then you should be able to do it.

One more thing, Xin? The result of integrating x in a half period of (0, π) is 2.

The second method is also universal (it may be beyond your scope, but you should be able to figure it out.

)

Also, direct derivation, if m is the variable on the left side of the equation, then the result on the left side of the equation is m? So we can take the derivative of m on the left side of the equation, and it is still a function of m after the derivative. The derivative result is shown below. The right side of the equation is a constant, and the derivative result is 0, and an equation is obtained.