Trig Identity Question (Basic)

Smythe · 05-10-2011 3:50pm #1

I've been working on this identity for hours and can't seem to get anywhere.

2 cosec x = (sin x)/(1 + cos x) + (1 + cos x)/(sin x)

I've been trying by making the LHS 2/sinx and also by replacing the 1's with (cos x)^2 + (sin x)^2, but I don't seem to be getting anywhere.

seandoiler · 05-10-2011 4:37pm

cross multiply on the rhs and simplify

Smythe wrote: »

I've been working on this identity for hours and can't seem to get anywhere.

2 cosec x = (sin x)/(1 + cos x) + (1 + cos x)/(sin x)

I've been trying by making the LHS 2/sinx and also by replacing the 1's with (cos x)^2 + (sin x)^2, but I don't seem to be getting anywhere.

Smythe · 05-10-2011 4:49pm

Thank you for that.

I've done that in one of the versions I was working on and got

(sin x ) (1+ cosx) for the denominator

I then further developed the equation and got:

(2+ 2cos x ) / [(sin x)(1 + cos x)]

That's as far as I can get.

Smythe · 05-10-2011 5:02pm

I'm ok now, I have the answer.

seandoiler · 05-10-2011 6:06pm

Smythe wrote: »

I'm ok now, I have the answer.

no problem, well done for working it out for yourself

Trig Identity Question (Basic)

Comments