SOLUTION: Determine the zeros, the degree, and the leading coefficient to graph this function. f(x) = (x2+2x)(x-3)

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: Determine the zeros, the degree, and the leading coefficient to graph this function. f(x) = (x2+2x)(x-3)      Log On


   



Question 1098319: Determine the zeros, the degree, and the leading coefficient to graph this function.
f(x) = (x2+2x)(x-3)

Found 3 solutions by greenestamps, ankor@dixie-net.com, KMST:
Answer by greenestamps(13198) About Me  (Show Source):
You can put this solution on YOUR website!

Factor the expression in the first set of parentheses to get

f%28x%29+=+%28x%29%28x%2B2%29%28x-3%29

With the function written this way, it is clear that the function is of degree 3 with leading coefficient 1 (leading term x^3), and with zeros at 0, -2, and 3.

Except for the exact y values, the degree, the leading coefficient, and the zeros together give a good picture of the general behavior of the graph.

graph%28300%2C200%2C-5%2C5%2C-8%2C8%2C%28x%29%28x%2B2%29%28x-3%29%29

Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
Determine the zeros, the degree, and the leading coefficient to graph this function.
f(x) = (x^2 + 2x)(x - 3)
Find the 0's
x^2 + 3x = 0
Factor out x
x(x + 3) = 0
x = 0
and
x = -3
@nd factor
x = 3
The zeros -3, 0, 3
The degree is 3 and leading coefficient is 1 but you can confirm that:
FOIL
(x^2+3x)*(x-3) = x^3 - 3x^2 + 3x^2 - 9x = x^3 - 9x
:
+graph%28+300%2C+200%2C+-6%2C+5%2C+-10%2C+10%2C+x%5E3-9x%29+


Answer by KMST(5328) About Me  (Show Source):
You can put this solution on YOUR website!
Usually, we write exponents following a ^ symbol.
Write x%5E2 as x^2 , x%5E3 as x^3 and sqrt%282%29 as sqrt(2),
and people will know what you mean.

You probably mean
f%28x%29=%28x%5E2%2B2x%29%28x-3%29

Factorinng further the x%5E2%2B2x=x%28x%2B2%29 factor,
you can re-write the fucntion as
f%28x%29=x%28x%2B2%29%28x-3%29
When one of those three factors is zero, f%28x%29=0 ,
so the zeros of the function are
highlight%28x=0%29 ,
x%2B2=0 <--> highlight%28x=-2%29 , and
x-3=0 <--> highlight%28x=3%29 .

Doing the indicated multiplication,
f%28x%29=%28x%5E2%2B2x%29%28x-3%29 can be re-written as f%28x%29=x%5E3-3x%5E2%2B2x%5E2-6x ,
and "collecting like terms, we simplify it to
f%28x%29=x%5E3-x%5E2-6x
The leading coefficient is the number part of the term of highest degree.
That is the implied/invisible highlight%281%29 in front of x%5E3 .
The degree is the greatest exponent: the highlight%283%29 in x%5E3 .