Question 64361: I need to graph the folliwing equations. Identify the vertex, intercepts and equation of the axis of symmetry. If a value is irrational , find a decimal approximation.
y=x^2-5x+4
Found 2 solutions by stanbon, ankor@dixie-net.com:
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! I need to graph the folliwing equations. Identify the vertex, intercepts and equation of the axis of symmetry. If a value is irrational , find a decimal approximation.
y=x^2-5x+4
----------------
Complete the square to put the equation in vertex form:
x^2-5x+? = y-4+?
x^2-5x+(5/2)^2 = y-4+(5/2)^2
(x-(5/2))^2=y-16/4+25/4
(x-(5/2))^2=y+(9/4)
Vertex: (5/2,-9/4)
Axis of symmetry: x=5/2
Cheers,
Stan H.
Answer by ankor@dixie-net.com(22740)  (Show Source):
You can put this solution on YOUR website! I need to graph the folliwing equations. Identify the vertex, intercepts and equation of the axis of symmetry. If a value is irrational , find a decimal approximation.
:
y = x^2 - 5x + 4
:
Make a table of x = -2 to + 6 and find y, the graph should look like this:
:
Find the x intercepts:
x^2 - 5x + 4 = 0
Factor:
(x-4)(x-1) = 0
x = +4
x = +1
:
Find the y intercept, this occurs when x = 0
y = 0^2 -5(0) + 4
y = 4 is the y intercept
:
Find the axis of symmetry:
using the form ax^2 + bx + c; axis of sym formula is x = -b/(2a)
In our equation a = 1; b = -5
x = -(-5)/(2*1)
x = +5/2
x = +2.5 is the axis of symmetry
:
Find the vertex, substitute for x = 2.5 and solve for y
y = 2.5^2 - 5(2.5) + 4
y = 6.25 - 12.5 + 4
y = -2.25
Vertex occurs at: x = +2.5, y = -2.25
:
you can confirm all this on the graph
|
|
|
