Write a function of the form Y=ax^2+c whose graph passes through the two given points (2,1),(5,-20)
1=4a+c from the first point.
-20=25a+c frm the second point
subtract equation1 from equation 2
-21=21a
a=-1
then c= 5
Y=-x^2+5
-20=25a+c frm the second point
subtract equation1 from equation 2
-21=21a
a=-1
then c= 5
Y=-x^2+5