Verify the identity: cos x + sin x tan x = sec x.

Question

Having trouble answering this one.

Answer 1

We know that tanx = sinx/cosx

secx = 1/cosx and sin^2x+cos^2x =1

Left hand side

= cosx+sinx tanx

= cosx+sinx(sinx/cosx)

= (cos^2x+sin^2x)/cosx

= 1/cosx

= secx

= right hand side.