I have an equation,

     y = 2x²+7,

Plotting y against x will give a quadratic graph, but plotting y against x² should give a straight line. The problem is I cannot do

  plot([y], x² = -5 .. 5);

It gives me an error

    Error, (in plot) unexpected option: x^2 = -5 .. 5

I have searched online but no links. Can anyone help with this.

Thanks

Fairoz