# Thread: Identity Help

1. ## Identity Help

If we establish an identity, -sinAcscA - sin^(2)A - cos^(2)A - tanAcotA would equal....

does it equal 3cos^(2)A - 1 or 3cos^(2)A - 2sin^(2)A?

2. Originally Posted by andy11
If we establish an identity, -sinAcscA - sin^(2)A - cos^(2)A - tanAcotA would equal....

does it equal 3cos^(2)A - 1 or 3cos^(2)A - 2sin^(2)A?
Who gave you the possible answers for this?
$-sin(A) \cdot csc(A) - sin^2(A) - cos^2(A) - tan(A) \cdot cot(A)$

$- sin(A) \cdot \frac{1}{sin(A)} - (sin^2(A) + cos^2(A)) - tan(A) \cdot \frac{1}{tan(A)}$

$-1 - (1) - 1 = -3$

I smell a typo somewhere...

-Dan

3. yeah your right.. i just checked with a friend.. i messed up on the first step.. thanks

4. Originally Posted by topsquark
Who gave you the possible answers for this?
$-sin(A) \cdot csc(A) - sin^2(A) - cos^2(A) - tan(A) \cdot cot(A)$

$- sin(A) \cdot \frac{1}{sin(A)} - (sin^2(A) + cos^2(A)) - tan(A) \cdot \frac{1}{tan(A)}$

$-1 - (1) - 1 = -3$

I smell a typo somewhere...

-Dan
that's what I got and i thought i was missing something. But since you got the same thing, I guess I was right