[(1+sinx)/cosx]*[sin2x/2cos²(π/4-x/2)]

问题描述:

[(1+sinx)/cosx]*[sin2x/2cos²(π/4-x/2)]

=[(1+sinx)/cosx]*{sin2x/[cos(π/2-x)+1]}=[(1+sinx)/cosx]*[2sinxcosx/(sinx+1)]=2sinx