作函数图像：

y=xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
y=xcosxx
y=xsinx

作函数图像：

y=(ln(1+x))/x

作函数图像：

y=-2(x^2)+3x

作函数图像：

y=-2(x^2)

作函数图像：

y=x^2