Question

极坐标方程pcosθ=2sin2θ表示的曲线为

Answer 1

ρcosθ=4sinθcosθ

ρ=4sinθ (cosθ≠0）

x=4sinθcosθ

y=4sinθsinθ

x^2+y^2=16(sinθcosθ)^2+16(sinθ)^4

=4*4(sinθ)^2

=4y

x^2+y^2-4y=0

x^2+(y-2)^2=4