Sine Cosine Pythagorean Identity  TOPIC_SOLVED

Trigonometric ratios and functions, the unit circle, inverse trig functions, identities, trig graphs, etc.

Sine Cosine Pythagorean Identity

Postby eliotmason on Tue Oct 29, 2013 10:37 pm

I am currently learning about Verifying trigonometric identities and it has been a really long time since I have taken any algebra. I wanted to know if I could modify the pythagorean identity to such:

So, the sine, cosine pythagorean identity is:



so that means that this is also true:



or...



So here is my question. I don't remember if I am allowed to do this but does that mean that this can also be true? -->



:confused:
eliotmason
 
Posts: 3
Joined: Tue Oct 29, 2013 5:36 am

Sponsor

Sponsor
 

Re: Sine Cosine Pythagorean Identity  TOPIC_SOLVED

Postby theshadow on Tue Oct 29, 2013 11:28 pm

eliotmason wrote:

so that means that this is also true:





does that mean that this can also be true? -->

Yes:
-1(cos^2(@)) = -1(-sin^2(@) + 1
-cos^2(@) = +sin^2(@) - 1
theshadow
 
Posts: 87
Joined: Sun Feb 22, 2009 11:12 pm


Return to Trigonometry