Finding area where r²sin(2θ) > 2√3 and r² < 4

  • Thread starter Thread starter nanostudy
  • Start date Start date
  • Tags Tags
    Area Plane
Join the discussion
Registration is free. Ask a follow-up in this thread, or start your own.
2 replies · 2K views
nanostudy
Messages
1
Reaction score
0

Homework Statement


Find the area of the region in the plane where, r2sin(2theta) >2(sq.root3) , r^2 < 4

Homework Equations

The Attempt at a Solution


To try to visualize the problem a little better I converted from r2sin(2theta) to 2xy. However I'm confused after this, since I don't know what the upper limit to integrate is. Also, in the context of the question what does r^2 < 4 mean? Thanks very much. :)
 
Physics news on Phys.org
nanostudy said:

Homework Statement


Find the area of the region in the plane where, r2sin(2theta) >2(sq.root3) , r^2 < 4

Homework Equations

The Attempt at a Solution


To try to visualize the problem a little better I converted from r2sin(2theta) to 2xy. However I'm confused after this, since I don't know what the upper limit to integrate is. Also, in the context of the question what does r^2 < 4 mean? Thanks very much. :)

Recall that [itex]r = \sqrt{x^2 + y^2}[/itex], so the inequality [itex]r^2 < 4[/itex] covers all points within a circle of radius 2 about the origin in the xy-plane. Sketch the graph of this bounding circle, and the graph of the bounding curve [itex]2xy = 2\sqrt{3}[/itex] (a rectangular hyperbola). Then shade in the regions that satisfy the inequality. Use the boundaries of those regions to define your integrals.
 
[itex]r^2< 4[/itex], in polar coordinates, is the same as "r< 2" since r is not negative. That is the interior of a circle, centered at the origin, with radius 2