(-2.5,6.1)(-2.5,3.1).....notice how ur x values are the same. This means that u have a vertical line which has an undefined slope.
IF ur y values would have been the same, u would have had a horizontal line which has a 0 slope.
Red line shows
y=x^2-4 , cause it's going through point (0,-4)
So blue line shows
y= -x^2+1 Point (1,0) belong to it , moreover x factor is negative , so the arms of parabola will go down
Have nice evenig :)
Greetings From Poland.
A equivelint ratio is when u can multi or divide by both sides