- #1
jd12345
- 256
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Homework Statement
Find the range of y = (cos2x - 1) / ( cos2x + cos x )
Homework Equations
The Attempt at a Solution
Well i tried the usual method. I cross multiplied and got a quadratic equation in cos x. Then it should have discriminant greater than zero so in the end i get (y-2)2 > 0 which is true for all y. So range is R? ( I don't have the answer)