sin x高次方公式

In=∫sin^nxdx=∫sin^(n-1)

x sinxdx=-∫sin^(n-1)

x dcosx=-cosxsin^(n-1)x+∫cosxdsin^(n-1)x=-cosxsin^(n-1)x+(n-1)∫cosxsin^(n-2)

xcosxdx=-cosxsin^(n-1)x+(n-1)∫cos²xsin^(n-2)xdx=-cosxsin^(n-1)x+(n-1)...