Question

prove (sinx-tanx)^2=(tan^2x)(cosx-1)^2

Answer 1

LS = (sinx - sinx/cosx)^2

= ( (sinxcosx - sinx)/cosx )^2
= ( sinx(cosx - 1) )^2 / cos^2 x
= (sin^2 x/cos^2 x)(cosx - 1)^2
= tan^2 x (cosx - 1)^2
= RS