How do you graph, label the vertex, axis of symmetry and x intercepts of y=(3x1)(x3)?

2 Answers
Jun 23, 2017

graph{(3x-1)(x-3) [-20, 20, -10, 10]}
Vertex = ( 53, 83)
Axis of symmetry = x=53
X-intercepts = (13,0)and(3,0)

Explanation:

Multiplying the two brackets we get the quadratic,
3x210x+3
Comparing with ax2+bx+c, we get
a=3,b=10,c=3
and the Discriminant = b24ac => 64
Co-ordinates of Vertex of parabola are (b2a,D4a)
plug the the values of a,b,c to get vertex of parabola.

Axis of symmetry is the x-coordinate of Vertex i.e
x=53

x-intercept of the parabola is basically the roots of equation.
Roots can be obtained by equating the function to 0.
(3x1)(x3)=0
either 3x1=0 or x3=0 (By Zero Product Rule)
this gives x=13,3
These are the x-intercepts.

Jun 23, 2017

X-intercept

x=13
x=3
Vertex (53,163)
Axis of symmetry x=53

Explanation:

Given -

y=(3x1)(x3)

X-intercept
At y=0

(3x1)(x3)=0

3x=1
x=13

x=3

y=3x2x9x+3
y=3x210x+3

Vertex

x=b2a=(10)2×3=106=53

At x=53

y=3(53)210(53)+3
y=3(259)503+3
y=253503+3
y=2550+93=163

Vertex (53,163)

Axis of symmetry x=53

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