Answer:
1526.8 ft ^3
Step-by-step explanation:
the volume of a cylinder formula is V=π x r^2 x h
= pi x 9^2 x 6
= pi x 81 x 6
=1526.8 ft ^3
Find the concavity changes of f(x).
Give the x-coordinates.
So, the answer to the multiple choice question is -1 and 5 since those points are where f''(x) changes sign.
Note: You can tell that you're supposed to find the concavity changes of f(x) and not f''(x) because from the graph it's obvious that the concavity of f"(x) doesn't change.
The given equation is: 
To find the line perpendicular to it, we interchange coefficients and switch the signs of one coefficient.
The equation to a line perpendicular to it is:
$ 2y-x=c$
where, $c$ is some constant we have determine using the condition given.
It passes through $(2,-1)$
Put the point in our equation:
$2(-1)-(2)=c$
$c=-2-2$
$c=-4$
The final equation is:
$\boxed{ 2y-x=-4}$
C is the answer you would want to use because (2, -4) is a solution to the equation.
Y=mx+b
M is the slope
B is the y intercept
In this case 4 is the slope and -9 is the y intercept