课本第10章10.1牙膏的销售量x1=-0.050.250.6000.250.200.150.05-0.150.150.200.100.400.450.350.300.500.500.40-0.05-0.05-0.100.200.100.500.60-0.0500.050.55;x2=5.506.757.255.507.006.506.755.255.256.006.506.257.006.906.806.807.107.006.806.506.256.006.507.006.806.806.505.755.806.80;y=7.388.519.527.509.338.288.757.877.108.007.898.159.108.868.908.879.269.008.757.957.657.278.008.508.759.218.277.677.939.26;scatter(x1,y,ro)scatter(x2,y,ro)(发现第一个符合正比例关系，第二个基本符合二次函数关系)输入：x=ones(30,l),xl,x2,(x2).人
