integral X Sin dalam kurung x kuadrat + 1 DX

InTegraL

Misal :
u = x² + 1
du/dx = 2x
x dx = 1/2 du

∫x sin (x² + 1) dx
= ∫sin u . 1/2 du
= 1/2 ∫-dcos u
= -1/2 cos u + C
= -1/2 cos (x² + 1) + C