(1 + sinx)(secx - tanx) = cos x

Answer 1

LS = secx - tanx + sinxsecx - sinxtanx
= 1/cosx - sinx/cosx + sinx/cosx - sin^2x/cosx
= 1/cosx - (1 - cos^x)/cosx
= (1 - 1 + cos^2x)/cosx
= cos^2x/cosx
= cosx
= RS