参数方程与普通方程互化
问题描述：
参数方程与普通方程互化
x=2t/(1+t^2)
y=(1-t^2)/(1+t^2)
答
x=2t/(1+t^2)y=(1-t^2)/(1+t^2)x^2=4t^2/(1+t^2)^2y^2=(1-t^2)^2/(1+t^2)^2=(1-2t^2+t^4)/(1+t^2)^2x^2+y^2=[4t^2+1-2t^2+t^4]/(1+t^2)^2=(t^2+1)^2/(1+t^2)^2=1所以该参数方程对应的普通方程是:x^2+y^2=1...