Question

Chapter 5: Find the vertex,

x-intercept, y-intercept and the line of
symmetry of the Quadratic functions
and use the graphs to describe them
completely. Use the list of attributes
for describing graphs.
y= x2 – 2x – 15

Answer 1

See below

Explanation:

X-intercepts

`f(x)=x^2-2x-15`

`0=x^2-2x-15`

`0=(x-5)(x+3)`

`x=5` and
`x=-3`

`(5,0)` and
`(-3,0)`

Y-intercept:

`f(x)=x^2-2x-15`

`f(0)=0^2-2(0)-15`

`f(0)=0-0-15`

`f(0)=-15`

`y=-15`

`(0,-15)`

Vertex:

`f(x)=x^2-2x-15`

`f(x)=x^2-2x+(1-16)`

`f(x)=x^2-2x+1-16`

`f(x)=(x^2-2x+1)-16`

`f(x)=(x-1)^2-16`

`f(x)=(x-h)^2+k`

`(h,k)`

`(1,-16)`

Line of Symmetry:

`x=h`

`x=1`