Trig Identities?

0 ⤊

If you have

-cos^2 + -sin^2x

does it equal a

-1 ?

2007-09-26 13:03:52 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics

3 answers

Yes

-cos^2(x) = - cos(x).cos(x) NOT (-cos(x)).(-cos(x))

To figure this out, use the identity to convert one of the terms.

-cos^2(x) + -sin^2(x)
-cos^2(x) - sin^2(x)
-cos^2(x) - (1 - cos^2(x))
-cos^2(x) - 1 + cos^2(x)
-1

2007-09-26 13:12:59 · answer #1 · answered by tkquestion 7 · 0⤊ 0⤋

Yes, since sin^2 x + cos^2 x = 1

2007-09-26 20:07:09 · answer #2 · answered by kindricko 7 · 0⤊ 0⤋

i would say yes

2007-09-26 20:09:09 · answer #3 · answered by shadoyaj 4 · 0⤊ 0⤋