x-Intercepts and y-Intercepts of Lines

This video involves x- and y-intercepts of linear equations. Topics include: finding intercepts, graphing a line using its intercepts, graphing horizontal and vertical lines, and interpreting intercepts of a real world function. George Woodbury is an author who teaches at College of the Sequoias in Visalia, CA.

Category:

Education

Tags:

• math
• algebra
• elementary algebra
• linear equations
• intercepts
• x-intercept
• y-intercept
• lines
• graphing lines
• vertical lines
• horizontal lines

[whiskylover1973]

sorry that should be 4x-x^3

[georgewoodbury]

To find x-int's, set the function equal to 0.

Set 4x-x^3 = 0.

Now factor out a common x.

x(4-x^2)=0

Now factor as a difference of squares.

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

Set each factor equal to 0 and solve.

x=0, x=-2, x=2

[whiskylover1973]

That's great, thank you for the help :)

[whiskylover1973]

What if you were finding the x-intercepts for:

f(x)=x-x^3

?