SOLUTION: Hi, I'm doing exam review and a crucial section I need to know I cannot remember. This question I'm unsure of how to attempt. Thanks to the person that solves it. Using the meth

Algebra.Com
Question 975640: Hi, I'm doing exam review and a crucial section I need to know I cannot remember. This question I'm unsure of how to attempt. Thanks to the person that solves it.
Using the method indicated, determine the minimum or maximum value of each of the following and state the X value for which it occurs.
A) y=x^2+8x-5 by partial factoring
B) y=-3x^2-12x+7 by completing the square

Answer by josgarithmetic(39617)   (Show Source): You can put this solution on YOUR website!
(A), partial factoring for max or min of y=x^2+8x-5, but what kind of method is "partial factoring"? I never heard of that. The quadratic polynomial you have on the right hand side is not factorable.

I would just use general solution to get the zeros, and find the x value in the middle.

Zeros:





, the zeros for the equation

Find Middle x value of the zeros:
Just same as finding the average of the zeros,



-
The corresponding y value:



, a minimum value.


(B):
Study the lessons on Completing The Square.
How to Complete The Square is included in this how-to-solve quadratic equation lesson.
Visually showing what Completing The Square means

RELATED QUESTIONS

I am taking pre-cal and we got a review packet for homework. I have this question, that i (answered by jim_thompson5910)
I keep looking at this problem, and I know it's basic, but I cannot remember how to solve (answered by rapaljer)
I know this is a very basic question, but I cannot remember if there is any way of... (answered by stanbon)
I'm working on my exam review and I can't figure out how to do this question. The... (answered by vleith)
Hi, I'm doing my Junior Cert next year and I have been practising sample papers but I... (answered by Cromlix)
can you please give me examples of problems that would be included on a college entrance... (answered by Earlsdon)
Hi! I need help writing this in slope-intercept form. Here is my question: Equation of... (answered by Alan3354)
im doing "zero and negaive exponents"... in need to "use the quotient of powers property (answered by wuwei96815)
Hi so basically I need to simplify all square roots and answers should not be decimals... (answered by math_helper,ikleyn)