How do you find the vertex and intercepts for #y = 2x^2#?

1 Answer
Nov 14, 2015

They are all at #(0,0)#.

Explanation:

Finding the vertex:
Use the formula #(-b/(2a), f(-b/(2a)))#, given the form of the parabola #f(x)=ax^2+bx+c#. In your case, #a=2,b=0# and #c=0#.
Here, #-b/(2a)=-0/(2*2)=0# and #f(-b/(2a))=f(0)=2(0)^2=0#.
Thus, the vertex is located at #(0,0)#.

Finding the X-intercept:
Plug in #0# for #y#.
#0 = 2x^2=>0=x^2=>0=x#
Then plug in #0# for #y# to determine the point of the intercept. We already know that if we plug in #0# for either point, we will receive #0# as our answer, so the X-intercept is #(0,0)#.

Finding the Y-intercept:
This is very similar to finding the X-intercept, in that we now plug in #0# for #x#, which we already know will result in the point #(0,0)#.

Alternative method: Graph the parabola and look at the vertex and intercepts.