What are the coordinates of the x-intercepts of the graph of y = 2x2 + 6x – 20
Favorites|Homepage
Subscriptions | sitemap
HOME > Mathematics > What are the coordinates of the x-intercepts of the graph of y = 2x2 + 6x – 20

What are the coordinates of the x-intercepts of the graph of y = 2x2 + 6x – 20

[From: ] [author: ] [Date: 11-10-11] [Hit: ]
All terms are multiples of two, so factor it out.x = - 5,The x-intercept(s) of the parabola (e.g. YOUR FUNCTION ABOVE) is/are the ( x,......
Please help!

-
Y = x^2 + 6x - 20 is a parabola opening up.

It is in standard form, y = ax^2 + bx + c

A quick peek at the discriminant, b^2 - 4ac,

6^2 - 4(2)(- 20) = 36 + 160 = 196, lets us know it has two real roots.


To solve, factor using FOIL.

2x^2 + 6x - 20 = 0

All terms are multiples of two, so factor it out.

2(x^2 + 3 - 10) = 0

2(x + 5)(x - 2) = 0

x = - 5, x = 2

-
y = 2x^ + 6x – 20

DEFINITION:
The x-intercept(s) of the parabola (e.g. YOUR FUNCTION ABOVE) is/are the ( x, y ) coordinates of the point(s) of the parabola where it intersects the x-axis. The y-value of the x-intercept(s) is always 0, if an x-intercept exists. If an x-intercept does not exist, then there are NO coordinates for an x-intercept.

step 1) set y = 0 to find x-intercepts
step 2) 0 = 2x^2 + 6x - 20
step 3) factor out 2 from the right side => 2(x^2 + 3 - 10) = 0
step 4) divide both sides by 2 ===> x^2 + 3 - 10 = 0
step 5) factor out the quadratic equation: (x + 5) (x - 2) = 0
step 6) set each factor to zero
x + 5 = 0 ==> x = -5
x - 2 = 0 ==> x = 2
step 7) since the y=0 for any x-intercept the coordinates or your x-intercepts are:
(-5, 0) and (2, 0)

I explained it in detail so you may learn the procedure and solve future similar problems on your own. Hope it is helpful.

-
2(x+5)(x-2)=0---->x=...
1
keywords: intercepts,of,coordinates,graph,are,20,ndash,What,the,What are the coordinates of the x-intercepts of the graph of y = 2x2 + 6x – 20
New
Hot
© 2008-2010 http://www.science-mathematics.com . Program by zplan cms. Theme by wukong .