How do you verify the identity 4 csc 2x = 2 csc^2x tan x?

1 Answer
Apr 28, 2015

We will be using a Trigonometric identity to prove this-
color(blue)(sin(2x) = 2sinxcosx

The left hand side is 4csc2x

= 4/(sin2x) (Because cscx = 1/sinx)

= 4/(2sinxcosx)

= color(green)(2/(sinxcosx)

The right hand side is 2 csc^2x tan x

= 2*(1/sin^2x)*(sinx/cosx) (Because tanx = sinx/cosx)

= color(green)(2/(sinxcosx)

Hence proved.