x^2+y^2=4设过P点与圆的切线方程为y=kx+√3-k|0+0+k-√3|/√k^2+1=2|k-√3|/+√k^2+1=2k-√3=2√k^2+1k^2-2√3k+3=4(k^2+1)k^2-2√3k+3=4k^2+43k^2+2√3k+1=0(√3k+1)^2=0√3k+1=0k=-√3/3所以切线方程为:y=-√3x/3+...