the fortaleza telescope in brazil is a radio telescope. its shape can approximated with the equation y=0.013x2 is the relationship between x and y linear? is it proportional? explain

Is the relationship between x and y linear?
No, the relationship between x and y is not linear, because x has power 2. To be a linear relationship the powers of x and y must be 1.
Is it proportional?
No, it is not proportional.
Only is proportional for x>0. For x<0 is inversily proportional.