Question 1151421
If the revenue function for selling q widgets is 

{{{r(q) =q(4187-5q)}}} dollars, 

find the {{{marginal}}}{{{ revenue}}} function, and find the marginal revenue when {{{q=135}}}:

we can find marginal revenue by finding the derivative of 

{{{r(q) =q(4187-5q)}}}
{{{r(q) =4187q-5q^2}}}

derivative is:

{{{R}}}'{{{(q) =4187-2*5q}}}
{{{MR=R}}}'{{{(q)=  4187 -10q}}}

then

{{{R}}}'{{{(135) =4187 -10 *135=4187-1350=2837}}}