The letters x and y represent rectangular coordinates Write
The letters x and y represent rectangular coordinates. Write the given equation using polar coordinates (r, theta). 5x^2 + 5y^2 = 2 Select the correct equation in polar coordinates below. r = 2/5(cos theta + sin theta) r^2 = 2/5 r^2 = 2/5(cos theta + sin theta) r = 2/5
Solution
5x2+5y2=2
5(x2+y2)=2
x=r cos theta, y=r sin theta
therefore
5(r2 cos 2 theta + r2 sin 2 theta=2
r2(5 cos2 theta +5sin2 theta)=2
r2=2/(5cos2theta +5sin2theta)
r2=2/(5(cos2 theta +sin2 theta))
r2 =2/5
correct option is B.
