Question

A company's revenue from selling x units of an item is given as
R
=1700x−x^2. If sales are increasing at the rate of 45 units per day, how rapidly is revenue increasing (in dollars per day) when 290 units have been sold?

Answer 1

R = 1700 - x^2
dR/dt = -2x dx/dt, but we are told that dx/dt = 45 units/day
= -2(290)(45) = ....

Your equation of R = 1700 - x^2 doesn't make sense.
Why would the Revenue decrease as the sales increase?
I assume that x represents sales.
You sure it wasn't R = 1700 + x^2 ?

look into it

Answer 2

A company's revenue from selling x units of an item is given as R=1700x−x^2. If sales are increasing at the rate of 45 units per day, how rapidly is revenue increasing (in dollars per day) when 290 units have been sold?
I am sure that R=1700x−x^2

Answer 3

Let A be the area of a circle with radius r. If dr/dt=2 , find dA/dt when r=2.

Answer 4

For the parametric curve x=t2;y=t3 ,

evaluate the curvature (2nd derivative) when t=3