29. 已知抛物线C:y2=4xC:y^{2}=4xC:y2=4x上一点P(x0P(x_{0}P(x0,y0)y_{0})y0),点A(3,21)A(3,\sqrt{21})A(3,21),则y022+2∣PA∣\frac{{y}_{0}^{2}}{2}+2\vert PA\vert2y02+2∣PA∣的最小值是((( )))