How do you prove 2tan(x)sec(x) = (cos^2x+sin^2x)/(1-sin(x)) - (1/(1+sin(x))) ?

1 Answer
Mar 6, 2018

Please refer to a Proof in the Explanation.

Explanation:

Since, cos^2x+sin^2x=1, we have,

(cos^2x+sin^2x)/(1-sinx)-1/(1+sinx),

=1/(1-sinx)-1/(1+sinx),

={1(1+sinx)-1(1-sinx)}/{(1-sinx)(1+sinx)},

=(1+sinx-1+sinx)/(1-sin^2x),

=(2sinx)/cos^2x,

=2*sinx/cosx*1/cosx,

=2tanxsecx, as desired!