You are here:
Algebra/algebra
Advertisement
Question
using the quadratic formula find the roots of this equation: x^2-4x-6=0
The quadratic formula is x = (-b +/- sqrt(b^2 - 4ac))/(2a) for ax^2 + bx + c = 0.
In this equation, a=1, b=-4, and c=-6.
This gives (4 +/- sqrt(16+24))/2.
since 15+24=40, and the sqrt(40) = 2*sqrt(10), we have (4 +/- 2*sqrt(10))/2.
The two cancels out gives 2 +/- sqrt(10).
That is, 2 + sqrt(10) and 2 - sqrt(10).
Related Articles
Algebra
Answers by Expert:
Scott A Wilson
Expertise
Any algebraic question you've got, like linear, quadratic, exponential, etc.
Experience
solving story problems
solving linear, parabolic, and 3rd order equations
solving equations with multiple variables
Publications
documents at Boeing
Education/Credentials
MS at math OSU in mathematics at OSU
BS at OSU in mathematical sciences (math, statistics, computer science)
Awards and Honors
both BS and MS degrees were given with honors
Past/Present Clients
students from all over since the 80's; over 1,000 in algebra
©2012 About.com, a part of The New York Times Company. All rights reserved.