All right, I think I've got it.
and if then after using the pythagorean theorem
we get 4^2 + 3^2 = 5^2
Luckily, in this case, I know the answer is
So I can see how the multiply to make
and then we can make it back into
And because of the identity property the answer is -24/25.
Does that seem right?
Look at what Mr. fantastic wrote:
you get this:
This is not the same as this:
We are saying that is in Quadrant IV, so
You figured out correctly that
So we substitute and get
I'll say it again: this is not the same as this:
I'm sorry if I sound irritated -- I can't tell you how many times I see errors in notation like this. If this was an assignment and I was grading it I would only give partial credit.