Question

How do you find the x and y intercepts for `f(x)=4x^2-36`?

Answer 1

`"x-intercepts "=+-3," y-intercept "=-36`

Explanation:

`"to find the intercepts, that is where the graph crosses"`
`"the x and y axes"`

`• " let x = 0, in the equation for y-intercept"`

`• " let y = 0, in the equation for x-intercepts"`

`x=0toy=0-36=-36larrcolor(red)"y-intercept"`

`y=0to4x^2-36=0`

`"add 36 to both sides and divide by 4"`

`4x^2=36rArrx^2=9`

`color(blue)"take the square root of both sides"`

`x=+-sqrt9larrcolor(blue)"note plus or minus"`

`x=+-3larrcolor(red)"x-intercepts"`