cosy = sqrt{sin

^{4}x + 4cos

^{2}x} - sqrt{cos

^{4}x + 4sin

^{2}x}

how can i simplify this equation using trig identities/formulas:

cosy = sqrt{sin^{4}x + 4cos^{2}x} - sqrt{cos^{4}x + 4sin^{2}x}

cosy = sqrt{sin

- stapel_eliz
**Posts:**1731**Joined:**Mon Dec 08, 2008 4:22 pm-
**Contact:**

I think we are just supposed to simplify the expression on the right side of the equation. The instructions are to "express y in terms of x"

- stapel_eliz
**Posts:**1731**Joined:**Mon Dec 08, 2008 4:22 pm-
**Contact:**

Skylar wrote:I think we are just supposed to simplify the expression on the right side of the equation. The instructions are to "express y in terms of x"

Then you're not supposed to simplify; you're supposed to solve for y.

A good start will be to apply the Pythagorean Identity to the quadric terms. For instance, restate (cos

Once you have the right-hand side simplified somewhat, you can take the inverse.