计算定积分 ∫(π/6→π/2)cos²xdx
1个回答

∫(π/6→π/2)cos²xdx

=∫(π/6→π/2)(1+cos2x)/2dx

=∫(π/6→π/2)1/2dx+1/2 ∫(π/6→π/2)cos2xdx

=1/2(π/2-π/6)+1/4∫(π/6→π/2)dsin2x

=π/6+1/4sin2x(π/6→π/2)

=π/6+1/4(0-√3/2)

=π/6-√3/8