SOLUTION: Could someone help me with these: What is the sum of the roots of the equation ax^2+bx+c=0 ? What is the product of their roots? How would I solve this equation x^3+2x^2+x+2=0,

Algebra.Com
Question 199257: Could someone help me with these:
What is the sum of the roots of the equation ax^2+bx+c=0 ?
What is the product of their roots?
How would I solve this equation x^3+2x^2+x+2=0, if -2 is a root?

Answer by stanbon(75887)   (Show Source): You can put this solution on YOUR website!
The roots are:
(-b/2a) + sqrt(b^2-4ac)/2a and (-b/2a) - sqrt(b^2-4ac)/(2a)
====================================================================
What is the sum of the roots of the equation ax^2+bx+c=0 ?
sum = 2(-b/2a) = -b/a
------------------------------------------------------------------
What is the product of their roots?
product is [b/2a]^2 - [sqrt(b^2-4ac)/2a]^2
= [b^2/4a^2] - [(b^2-4ac)/(4a^2)
------------------------------------------------------------------
How would I solve this equation x^3+2x^2+x+2=0, if -2 is a root?
Use synthetic division:
-2)....1....2....1....2
.........1...0....1....|..0
Quotient: x^2 +1
Remainder:0
------------------------
Solving x^2+1 = 0
(x+i)(x-i) = 0
==========================
Solutions: x = -2, x = i, x = -i
------------------------------------------------------------------
Cheers,
Stan H.

RELATED QUESTIONS

what is the sum of the roots of the equation ax exponent 2+bx+c=0? (answered by Earlsdon)
What is the sum of the roots of the equation... (answered by jim_thompson5910,stanbon)
What is the sum of the roots of the equation ax^2 + bx + c... (answered by htmentor)
What is the sum of the roots of the equation ax(squared) +bx +c... (answered by Alan3354)
what is the sum of roots of... (answered by jim_thompson5910)
i am asked what are the sum of the roots of the equation ax^2+bx+c=0 is the answer1 i... (answered by jsmallt9)
what are the product of the roots of the equation ax^2+bx+c=0. im not sure how this is... (answered by josmiceli)
4) (a) What is the sum of the roots of the equation ax^2 + bx + c = 0? (b)... (answered by stanbon)
what is the sum of the roots of the quadratic equation: ax^2 + bx + c = 0, where a, b,... (answered by Fombitz)