Question

Determine the intercepts and use symmetry to assist in sketching the graph of the equation y=3x-x^2

Answer 1

rewrite: y= -x^2 +3x
x symmetry = -3/(-2) = 3/2
y = -(3/2)^2 + 3(3/2)
= (-9/4) + (9/2)
= 9/4
vertex: ( 3/2, 9/4 )
if x= 0 , y intercept:=0
-x^2 +3x = 0
-x(x -3)
x intercept : x= 3 or x= 0