[求助]请大虾帮忙解决个曲线拟合问题！

[Shine_1206]

各位大侠：
我在实验中得出一组数据，
x=【0.0,31.6,63.2,94.7,126.3,157.9,189.5,221.1,252.6,284.2,315.8,347.4,378.9,410.5,442.1,473.7,505.3,536.8,568.4,600.0,600.0];
y=[0.0,4.12,4.70,3.28,-0.73,-4.32,-5.76,-5.33,-5.06,-4.95,-3.62,-2.40,-0.76,-0.88,-0.81,-0.66,0.05,1.17,2.16,3.10,3.71,0.0];
我现在想求出根据这些点画出的曲线与X轴的交点，该怎么做呢？
急啊~~ 谢谢各位大侠了！在线等~