SOLUTION: Put Into Vertex Form: A)2x^2+3x+5 B)3x^2-4x+5 C)2x^2-3x+3 Please Help God Bless you.

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: Put Into Vertex Form: A)2x^2+3x+5 B)3x^2-4x+5 C)2x^2-3x+3 Please Help God Bless you.      Log On


   



Question 898531: Put Into Vertex Form:
A)2x^2+3x+5
B)3x^2-4x+5
C)2x^2-3x+3
Please Help
God Bless you.

Found 2 solutions by josgarithmetic, Edwin McCravy:
Answer by josgarithmetic(39621) About Me  (Show Source):
You can put this solution on YOUR website!
Use Completing The Square. This is explained here:

What is Completing The Square

How to Complete The Square

Answer by Edwin McCravy(20060) About Me  (Show Source):
You can put this solution on YOUR website!
I'll just do the second one.  You do the others the same way:

y%22%22=%22%223x%5E2-4x%2B5

Factor 3 out of the first two terms only.  Since 4 is not 
divisible by 3 and we have to take out a 3 anyway, we must 
divide the 4 by 3 and get a fraction. 

y%22%22=%22%223%28x%5E2-expr%284%2F3%29x%29%2B5

Next we complete the square inside the parentheses:

1. Multiply the coefficient of the term in x, which is -4%2F3,
   by 1%2F2, getting expr%28-4%2F3%29%2Aexpr%281%2F2%29=-4%2F6=-2%2F3
2. Square this %28-2%2F3%29%5E2=4%2F9
3. Add and subtract 4%2F9 inside the parentheses:

y%22%22=%22%223%28x%5B%22%22%5D%5E2-expr%284%2F3%29x%2B4%2F9-4%2F9%29%2B5

Group the first three terms in smaller parentheses inside the
larger parentheses:

y%22%22=%22%223%28%28x%5E2-expr%284%2F3%29x%2B4%2F9%29-expr%284%2F9%29%5B%22%22%5D%29%2B5

The inner parentheses trinomial factors like this:x%5E2-expr%284%2F3%29x%2B4%2F9=%28x-2%2F3%29%28x-2%2F3%29=%28x-2%2F3%29%5E2

y%22%22=%22%223%28%28x-2%2F3%29%5E2%5B%22%22%5D-4%2F9%29%2B5
 
Now we distribute to remove the large parentheses, leaving the smaller
parentheses intact:

y%22%22=%22%223%28x-2%2F3%29%5E2-3%2Aexpr%284%2F9%29%2B5

Then we complete the fraction work on the end.
Cancel the 3 into the 9 and we have

y%22%22=%22%223%28x-2%2F3%29%5E2-4%2F3%2B5

Get a common denominator of 3 by multiplying the 5 by 3%2F3

y%22%22=%22%223%28x-2%2F3%29%5E2-4%2F3%2B15%2F3

And the final vertex form is:

y%22%22=%22%223%28x-2%2F3%29%5E2%2B11%2F3

Edwin