# Related Rates Question

• December 19th 2011, 11:37 AM
djmordigal
Related Rates Question
Hello,

I'm having trouble with this related rates problem:
Two sides of a triangle are 4m and 5m in length and the angle between them is increasing at a rate of 0.06rad/s (radians per second). Find the rate at which the area of the triangle is increasing when the angle between the sides of fixed length is $pi/3$.
• December 19th 2011, 11:52 AM
skeeter
Re: Related Rates Question
Quote:

Originally Posted by djmordigal
Hello,

I'm having trouble with this related rates problem:
Two sides of a triangle are 4m and 5m in length and the angle between them is increasing at a rate of 0.06rad/s (radians per second). Find the rate at which the area of the triangle is increasing when the angle between the sides of fixed length is $pi/3$.

$A = \frac{1}{2} ab \sin{\theta}$ , where a and b are the side lengths and $\theta$ is the angle between them.

sub in your constants and take the time derivative ...