If the price at which x units can be sold is given by the equation p=15-4 ln x, approximate the marginal revenue when x=7.
dp/dx=-4/x
To approximate the marginal revenue when x=7, we need to find the derivative of the given equation with respect to x, and then substitute x=7 into the resulting expression.
Step 1: Find the derivative of the equation p=15-4 ln x with respect to x.
The derivative of ln x is 1/x, so the derivative of -4 ln x with respect to x is -4/x. Therefore, the derivative of p=15-4 ln x with respect to x is -4/x.
Step 2: Substitute x=7 into the derivative expression.
Substituting x=7 into the derivative expression, we have:
-4/7
So, the approximate marginal revenue when x=7 is -4/7.