# Math Help - Trigometric problem!

1. ## Trigometric problem!

Hi, wondering if somebody could help me with this question,

Use trigometric and hyperbolic identities to solve trigonometric equations.

given that -15 cos(power2)x + 7 sinx + 11 = 0

Solve for x between 0deg and 360deg

Any help appreciated, been stressing with this all day.

Thanks.

2. ## Re: Trigometric problem!

Originally Posted by imonlyhuman
Hi, wondering if somebody could help me with this question,
Use trigometric and hyperbolic identities to solve trigonometric equations.

given that $-15 \cos^2x + 7 \sin x + 11 = 0$

Solve for x between 0deg and 360deg
Write it as $-15(1-\sin^2(x))+7\sin(x)+11=0$

Now you have $15y^2+7y-4=0$

3. ## Re: Trigometric problem!

This is where i get confused.. what i do next after 15y^2 + 7y - 4=0.

Thanks.

4. ## Re: Trigometric problem!

Originally Posted by imonlyhuman
This is where i get confused.. what i do next after 15y^2 + 7y - 4=0.