x=sint∫1/[1+√(1-x²)]dx= ∫1/[1+√(1-sin²t)]dsint= ∫cost/(1+cost)dt=∫1-1/(1+cost)dt=t-1/2 ∫1/cos²(t/2)dt=t-tan(t/2)/2+C=t-sint/[(1+√(1-sin²t)]+C=arcsinx-x/[(1+√(1-x²)]+C
