Answer:

Step-by-step explanation:
The given cylindrical equation is

Multiply both sides by r.
.... (1)
The required formulas are

Substitute
in equation (1).


Add 1 on both sides.

![[\because (a-b)^2=a^2-2ab+b^2]](https://tex.z-dn.net/?f=%5B%5Cbecause%20%28a-b%29%5E2%3Da%5E2-2ab%2Bb%5E2%5D)
It is the equation of a circle centered at (0,1) with radius 1.
Therefore, the equation in rectangular coordinates is
.
C. Is try correct answer
See example in the attached picture
Answer: I got 32
Step-by-step explanation:
I got 32
There is no real shortcut in learning integration formulas. You should take time learning and understanding how the formulas are derived until you are familiar with the formulas and you can easily recall the formulas. Hope this answers the question.
Check picture below, solve for "x" and "y"
unless you've already covered the 30-60-90 triangle, then check your book on them, to see the ratios, using the 30-60-90 ratios is simpler