The marketing research department for a computer company used a large city to test market their new product.
They found that the relationship between the price $p$ and the demand $x$ was given approximately by $$p = 1161 - 0.15 x^2.$$

Find $R(x)$, the revenue function.

$R(x)$ =

Now use the revenue function to do the following:

(A) Find the average of the $x$ values of all local maxima of $R(x)$.
Note: If there are no local maxima, enter -1000.

Average of $x$ values =

(B) Find the average of the $x$ values of all local minima of $R(x)$.
Note: If there are no local minima, enter -1000.

Average of $x$ values =

(C) Use interval notation to indicate where $R(x)$ is concave up.

Note: Enter 'I' for $\infty$, '-I' for $-\infty$, and 'U' for the union symbol.
If you have extra boxes, fill each in with an 'x'.
Concave up:

(D) Use interval notation to indicate where $R(x)$ is concave down.

Concave down: