Eliotmason
New member
- Joined
- Oct 29, 2013
- Messages
- 7
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:
\(\displaystyle \sin ^{2}\theta + \cos ^{2}\theta = 1\)
so that means that this is also true:
\(\displaystyle \cos ^{2}\theta = 1 - \sin^{2}\theta\)
or...
\(\displaystyle \cos ^{2}\theta = -\sin^{2}\theta + 1\)
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? -->
\(\displaystyle -\cos ^{2}\theta = \sin^{2}\theta - 1\)
So, the sine, cosine pythagorean identity is:
\(\displaystyle \sin ^{2}\theta + \cos ^{2}\theta = 1\)
so that means that this is also true:
\(\displaystyle \cos ^{2}\theta = 1 - \sin^{2}\theta\)
or...
\(\displaystyle \cos ^{2}\theta = -\sin^{2}\theta + 1\)
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? -->
\(\displaystyle -\cos ^{2}\theta = \sin^{2}\theta - 1\)