定积分s(π/2,0)cos^3xdx

问题描述:

定积分s(π/2,0)cos^3xdx

∫(0 π/2) cos³x dx
=∫(0 π/2)cosxcos²x dx
=∫(0 π/2)(1-sin²x) d(sinx)
=sinx -sin³x/3 (0 π/2)
=(1 -1/3)-(0-0)
=2/3