点（2,π/2）转化为直角坐标系的坐标(x,y)x=ρ ×cosθ=2×cosπ/2=2×cos90°= 0y=ρ ×sinθ=2×sinπ/4=2×sin90°= 2 (2,π2)的直角坐标为：（0,2）.曲线ρ=2sinθ转化为直角坐标方程：p=2sinθ; p^2=2psinθ; x...