Question

Find the length of the polar curve r=cos^3(theta/3)

Answer 1

cos^3 theta3 then goes to RHS so it become zero

so cos^3 theta=0

since cos0° = 1

so cos^3 theta = 1

taking cube root both side

so cos theta = cos 1

so on comparing,

theta = 1°

thus, radius is 1