Question #e138e

1 Answer
Dec 13, 2017

#r= sqrt((4cot(theta)+2)/(1+2sin^2(theta)))#

Explanation:

Here is the graph of the equation #x^2= 4x/y-3y^2+2#:

www.desmos.com

Now we shall begin the conversion.

Substitute #cot(theta)# for #x/y# and move #-3y^2# to the left:

#x^2+3y^2= 4cot(theta)+2#

Substitute #rcos(theta)# for x:

#(rcos(theta))^2+3y^2= 4cot(theta)+2#

Substitute #rsin(theta)# for y:

#(rcos(theta))^2+3(rsin(theta))^2= 4cot(theta)+2#

Regroup the left:

#(cos^2(theta))+3sin^2(theta))r^2= 4cot(theta)+2#

#(cos^2(theta))+sin^2(theta)+2sin^2(theta))r^2= 4cot(theta)+2#

#(1+2sin^2(theta))r^2= 4cot(theta)+2#

Divide both sides by #(1+2sin^2(theta))#:

#r^2= (4cot(theta)+2)/(1+2sin^2(theta))#

Use the square root on both sides:

#r= sqrt((4cot(theta)+2)/(1+2sin^2(theta)))#

Here is a graph of the converted equation:

www.desmos.com

Please observe that the graph of the equation before the conversion is identical to the graph of the equation after the conversion.