# Thread: Need urgent help with Related Rates

1. ## Need urgent help with Related Rates

Could anyone help me by solving this step by step so I can see what you did there?
Thank you so much in advance.

2. R = 110q - q^2/200

dq/dt = 55 the rate production is increasing and q = 400

Now we differentiate with respect to time -- note d(q^2)/dt = 2q dq/dt

dR/dt = 110dq/dt -q/100 dq/dt

dR/dt = 110(55)-(400/100)(55)

dR/dt = 6050 - 220 = 5830dollars/day

3. Originally Posted by Calculus26
R = 110q - q^2/200

dq/dt = 55 the rate production is increasing and q = 400

Now we differentiate with respect to time -- note d(q^2)/dt = 2q dq/dt

dR/dt = 110dq/dt -q/100 dq/dt

dR/dt = 110(55)-(400/100)(55)

dR/dt = 6050 - 220 = 5830dollars/day
Thank you so much Calculus26. I'm just uncertain about the last answer, a friend of mine told it can't be \$5830. He said that I might wanna try plugging in the derivative, but I 'm not sure what I'm getting wrong here.
Any ideas?