常见的三角函数的不定积分:
1、sinx的不定积分:sinx=(1-cos2x)/2∫sinx dx=∫(1-cos2x)/2 =1/2 - 1/2·∫cos2xdx=1/2 - 1/4·∫cos2xd(2x)=1/2 - 1/4·sin2x+C
2、∫sinx dx = -cos x + C;∫cosx dx = sinx + C;∫tanx dx = ln |secx| + C;∫cotx dx = ln |sinx| + C;∫secx dx =ln |secx + tanx| + C;∫cscxdx = ln |cscx - cotx| + C;∫sinx dx =1/2x - 1/4 sin 2x + C;∫cosx dx =1/2 + 1/4sin2x + C;∫tanx dx =tanx – x + C;∫cotx dx =- cotx – x + C;∫secx dx =tanx + C;∫cscx dx =- cotx + C