# Trigometric problem!

• May 23rd 2012, 09:43 AM
imonlyhuman
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. (Headbang) (Crying)

Thanks. (Hi)
• May 23rd 2012, 09:54 AM
Plato
Re: Trigometric problem!
Quote:

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 $15y^2+7y-4=0$
• May 24th 2012, 11:13 AM
imonlyhuman
Re: Trigometric problem!

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

Thanks.
• May 24th 2012, 11:25 AM
skeeter
Re: Trigometric problem!
Quote:

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