Http://www.pierce.ctc.edu/staff/dlippman/mathinsociety/Finance1.0.pdf I think this will help
Count change of signs to tell positive roots
then replace x with -x and evaluate, then count change in sign for negative roots
initially
+, -, -, +, +, -
3 changes
3 or 1 positive roots
replacing x with -x
-,-,+,+,-,-
2 changes
2 or 0 negative roots
B is answer
Identify the slope, m. This can be done by calculating the slope between two known points of the line using the slope formula.
Find the y-intercept. This can be done by substituting the slope and the coordinates of a point (x, y) on the line in the slope-intercept formula and then solve for b.
Assuming you're just computing the volume, i.e.

we should convert to cylindrical coordinates first, setting

so that the volume is given by

which has a value of

.