Answer:
1.26 m^2 / s.
Step-by-step explanation:
The area A of the triangle = 1/2*7*12 sin x Β = 42 sin x where x Β is the angle between the lines.
Relation between the rates is
dA/dt Β + dA/dx * dx/dt
We are given that dx /dt = 0.06 rad/s.
A = 42 sin x
dA/dx = 42 cos x
So dA/dt = 42 cos x * 0.06
When x = Ο/3 Β ( I am assuming that Ο 3 means Ο divided by 3 ):
dA/dt = 42 cos Ο/3 * 0.06
= 1.26 m^2/s.
