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Thursday, November 27, 2014

Sketching the Graph of a Polynomial, 7

Category: Analytic Geometry

"Published in Vacaville, California, USA"

Sketch the graph of a polynomial:


Solution:

Consider the given equation above   


Did you notice that the given equation has a common factor which is x⁵? Let's factor the above equation as follows 



and then it is factorable by the difference of two squares as follows 



If we set y = 0, then the x-intercepts of the given equation are 0, -3, and 3.

If we set x = 0, then the y-intercept of the given equation is
 
 
 

Since we now the x-intercept, then we can sketch the location or direction of a curve as follows 

If x < -3, then y = (-)³(-)(-) = (-)
If -3 < x < 0, then y = (-)³(+)(-) = (+)
If 0 < x < 3, then y = (+)³(+)(-) = (-)
If x > 3, then y = (+)³(+)(+) = (+)

Here's the graph of a polynomial:    

Photo by Math Principles in Everyday Life