Question

f(x)=x^2-7x+9 Find the x and y intercept

Answer 1

idk if this will help but

f(x + h) − f(x)
h
For f(x) = 2x + 3 we have:
f(x + h) − f(x)
h
=
[2(x + h) + 3] − [2x + 3]
h
=
2x + 2h + 3 − 2x − 3
h
=
✚2✚x + 2h + 3✁ − ✚2✚x − 3✁
h
=
2h
h
= 2

Answer 2

The y intercept is when x=0
So just find f(0)

Answer 3

The x intercept requires that we try and factorise the quadratic

Answer 4

remember f(x) and y are interchangeable.

for the y intercept let x = 0

so you have

\[y = 0^2 -7 \times 0 + 9\]

for the x-intecepts you have to set y = 0 and solve for x.

\[0 = x^2 - 7x + 9\]

and looking at this equation, you'll need the general quadratic formula

\[x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}\]

you have a = 1, b = -7 and c = 9

just substitute and calculate the values.

hope it helps

Answer 5

x^2 -7x +9 = (x+a)^2+b

Answer 6

did you work out the intercepts?