How do you graph f(x) = 2x^2 – 2 by plotting points?

1 Answer
May 1, 2017

"see explanation"

Explanation:

"select values of x and substitute into equation for values of y"

"the x-intercepts can be found by equating f(x) to zero"

rArr2x^2-2=0rArr2(x^2-1)=0

rArr2(x-1)(x+1)=0

rArrx=-1 , x=1larrcolor(red)" x-intercepts"

f(color(red)(0))=0-2=-2rArr(0,-2)larrcolor(red)" y-intercept"

f(color(red)(2))=8-2=6rArr(2,6)

f(color(red)(-2))=8-2=6rArr(-2,6)

Plot the x / y intercepts plus the other 2 points. Draw a smooth curve through them for the graph.
graph{2x^2-2 [-10, 10, -5, 5]}