SOLUTION: Evaluate each function for the value specified 4. f (x)= x^3 + 2x^2 - 7x+ 9; find (a) f (-2), (b) f (0), and (c) f (2).

Algebra ->  Graphs -> SOLUTION: Evaluate each function for the value specified 4. f (x)= x^3 + 2x^2 - 7x+ 9; find (a) f (-2), (b) f (0), and (c) f (2).       Log On


   

Question 124405: Evaluate each function for the value specified


4. f (x)= x^3 + 2x^2 - 7x+ 9; find

(a) f (-2), (b) f (0), and (c) f (2).

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

a)


Let's evaluate f%28-2%29


f%28x%29=x%5E3%2B2x%5E2-7x%2B9 Start with the given function.


f%28-2%29=%28-2%29%5E3%2B2%28-2%29%5E2-7%28-2%29%2B9 Plug in x=-2. In other words, replace each x with -2.


f%28-2%29=%28-8%29%2B2%28-2%29%5E2-7%28-2%29%2B9 Evaluate %28-2%29%5E3 to get -8.


f%28-2%29=%28-8%29%2B2%284%29-7%28-2%29%2B9 Evaluate %28-2%29%5E2 to get 4.


f%28-2%29=%28-8%29%2B8-7%28-2%29%2B9 Multiply 2 and 4 to get 8


f%28-2%29=%28-8%29%2B8%2B14%2B9 Multiply -7 and -2 to get 14


f%28-2%29=23 Now combine like terms


-----------Now let's evaluate another value---------

b)

Let's evaluate f%280%29


f%28x%29=x%5E3%2B2x%5E2-7x%2B9 Start with the given function.


f%280%29=%280%29%5E3%2B2%280%29%5E2-7%280%29%2B9 Plug in x=0. In other words, replace each x with 0.


f%280%29=%280%29%2B2%280%29%5E2-7%280%29%2B9 Evaluate %280%29%5E3 to get 0.


f%280%29=%280%29%2B2%280%29-7%280%29%2B9 Evaluate %280%29%5E2 to get 0.


f%280%29=%280%29%2B0-7%280%29%2B9 Multiply 2 and 0 to get 0


f%280%29=%280%29%2B0%2B0%2B9 Multiply -7 and 0 to get 0


f%280%29=9 Now combine like terms


-----------Now let's evaluate another value---------

c)

Let's evaluate f%282%29


f%28x%29=x%5E3%2B2x%5E2-7x%2B9 Start with the given function.


f%282%29=%282%29%5E3%2B2%282%29%5E2-7%282%29%2B9 Plug in x=2. In other words, replace each x with 2.


f%282%29=%288%29%2B2%282%29%5E2-7%282%29%2B9 Evaluate %282%29%5E3 to get 8.


f%282%29=%288%29%2B2%284%29-7%282%29%2B9 Evaluate %282%29%5E2 to get 4.


f%282%29=%288%29%2B8-7%282%29%2B9 Multiply 2 and 4 to get 8


f%282%29=%288%29%2B8-14%2B9 Multiply -7 and 2 to get -14


f%282%29=11 Now combine like terms