How do you use the important points to sketch the graph of #y = 3( x + 1 ) ^2 -4#?

1 Answer
Jul 30, 2017

The important points are:
a. Vertex.
the coordinates of the vertex are: (- 1, - 4).
Since a > 0, the parabola graph opens upward, the vertex is also the minimum.
b. y-intercept
Make x = 0, we get the coordinate of the y-intercept:
y-int = 3 - 4 = 1
c. x- intercepts.
Make y = 0 and solve for x.
#(x + 1)^2 = 4/3#
#x + 1 = +- 2/sqrt3 = +- (2sqrt3)/3#
#x = - 1 +- (2sqrt3)/3#