- #1

DryRun

Gold Member

- 838

- 4

**Homework Statement**

Find area of regions bounded by

x^2 + y^2 = 9, y = 2x, x-axis in the first quadrant

**The attempt at a solution**

So, i drew the graph of y against x in my copybook, and circle with origin (0,0), radius = 3 units. The line y = 2x cuts through the circle.

Transforming to polar coordinates, the new limits are:

0≤θ≤tan^-1(3) and 0≤r≤3

[tex]\int\int rdrd\theta[/tex]

After integration, i get the final answer: (9/2)tan^-1(3)

However, the answer in my notes is: (9/2)tan^-1(2). Did i copy the wrong answer or is my work wrong? I'm not sure.