# Thread: 1-cos^2 a + tan^2 a * cos^2 a

1. ## 1-cos^2 a + tan^2 a * cos^2 a

Hello,
I can't find functions for $1-cos^2 {\alpha} + tan^2 {\alpha} * cos^2 {\alpha}$
I found that $1-cos^2 {\alpha} = sin^2 {\alpha}$
But where i can find functions for $tan^2 {\alpha} * cos^2 {\alpha}$?

Thanks.

2. $sin^{2}(a)+\frac{sin^{2}(x)}{cos^{2}(x)}\cdot cos^{2}(a)=2sin^{2}(a)$

3. Originally Posted by dzein
Hello,
I can't find functions for $1-cos^2 {\alpha} + tan^2 {\alpha} * cos^2 {\alpha}$
I found that $1-cos^2 {\alpha} = sin^2 {\alpha}$
But where i can find functions for $tan^2 {\alpha} * cos^2 {\alpha}$?

Thanks.
$\tan^2{\alpha} \cdot \cos^2{\alpha} = \sin^2{\alpha}$

4. Thankies