今有一题:试说明曲线方程(?)(t∈R)中参数t的几何意义。根据思考问题的方法不同,有以下两种解法。解法一:消去参数t,化题设的方程为y~2=16x,这是以原点为顶点,以x轴的正半轴为对称轴的抛物线(如图)。在抛物线上 Now there is a question: Try to explain the geometric meaning of the parameter t in the curve equation (?)(t∈R). According to different ways of thinking about problems, there are the following two solutions. Solution One: Eliminate the parameter t, and set the equation for the problem to y~2=16x. This is a parabola with the origin as the vertex and the x-axis positive semi-axis as the symmetry axis (see the figure). On the parabola