# Thread: Can someone verify this is correct? - Trig proof.

1. ## Can someone verify this is correct? - Trig proof.

Hey guys can you verify my logic?

If asec(x)=1+tan(x)
and bsec(x)=1-tan (x)
prove a^2 + b^2 = 2

a = 1+tan(x) / sec(x)
a = 1+tan(x) * cos(x)
a = cos + sin

b = 1-tan(x) / sec(x)
b = 1-tan(x) * cos(x)
b = cos(x) - sin(x)

(cos(x)+sin(x))^2 + (cos(x)-sin(x))^2

= 2cos^2(x) + 2sin^2(x) + 2cos(x)sin(x) - 2cos(x)sin(x)
= 2( cos^2(x) + sin^2(x) )
= 2(1)
= 2

2. ## Re: Can someone verify this is correct? - Trig proof.

You are absolutely right. Make use of brackets. for example
1 - tanx * cos x is not correct you should write ( 1 - tanx ) * cos x