Asked by Serena

Verify the following identity:

(sin2x)/sin - (cos2x)/cosx=secx


Answered by Reiny
LS = (sin2x)/sin - (cos2x)/cosx
= 2sinxcox/sinx - (2cos^2 x - 1)/cosx
= 2cosx - (2cos^2 x/cosx - 1/cosx)
= 2cosx - 2cosx + 1/cosx
= secx
= RS