SOLUTION: Given f(x)=-x^3-x^2-3x+1 f(-1), f(0), f(2)

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Question 87046: Given f(x)=-x^3-x^2-3x+1
f(-1), f(0), f(2)
Found 2 solutions by scianci, jim_thompson5910:
Answer by scianci(186) About Me  (Show Source):
You can put this solution on YOUR website!
Plug -1 , 0 and 2 in for x, one by one.

Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!

First lets evaluate f%28-1%29



f%28x%29=-x%5E3-x%5E2-3x%2B1 Start with the given polynomial


f%28-1%29=-%28-1%29%5E3-%28-1%29%5E2-3%28-1%29%2B1 Plug in x=-1


f%28-1%29=-%28-1%29-%28-1%29%5E2-3%28-1%29%2B1 Raise -1 to the third power to get -1


f%28-1%29=-%28-1%29-%281%29-3%28-1%29%2B1 Raise -1 to the second power to get 1


f%28-1%29=-%28-1%29-%281%29--3%2B1 Multiply 3 by -1 to get -3


f%28-1%29=4 Now combine like terms

So when x=-1 y=4



Now lets evaluate f%280%29



f%28x%29=-x%5E3-x%5E2-3x%2B1 Start with the given polynomial


f%280%29=-%280%29%5E3-%280%29%5E2-3%280%29%2B1 Plug in x=0


f%280%29=-%280%29-%280%29%5E2-3%280%29%2B1 Raise 0 to the third power to get 0


f%280%29=-%280%29-%280%29-3%280%29%2B1 Raise 0 to the second power to get 0


f%280%29=-%280%29-%280%29-0%2B1 Multiply 3 by 0 to get 0


f%280%29=1 Now combine like terms

So when x=0 y=1





Now lets evaluate f%282%29



f%28x%29=-x%5E3-x%5E2-3x%2B1 Start with the given polynomial


f%282%29=-%282%29%5E3-%282%29%5E2-3%282%29%2B1 Plug in x=2


f%282%29=-%288%29-%282%29%5E2-3%282%29%2B1 Raise 2 to the third power to get 8


f%282%29=-%288%29-%284%29-3%282%29%2B1 Raise 2 to the second power to get 4


f%282%29=-%288%29-%284%29-6%2B1 Multiply 3 by 2 to get 6


f%282%29=-17 Now combine like terms

So when x=2 y=-17

Here is a table: 





 xy


 -14
 

 01
 

 2-17