Question 902930
tan x + sin x = m and tan x –sin x = n, then (m 2  – n 2 ) is equal

m^2= (tan x+sin x)^2

n^2= (tan x-sin x)^2

m^2-n^2= (tan x+sin x)^2 -(tan x-sin x)^2

= tan^2x+2tanxsinx+sin^2x-(tan^2x-2tanx.sinx+sin^2x)

= tan^2x+2tanxsinx+sin^2x-tan^2x+2tanx.sinx-sin^2x

= 4 tanx sinx