SOLUTION: I need to solve this help solving these two problems, I am stuck I came up with x=2 for the first and (-3,1) for the second can you please help. 1. If {{{f(x)=4x^2-3x+2}}}, find f

Algebra ->  Functions -> SOLUTION: I need to solve this help solving these two problems, I am stuck I came up with x=2 for the first and (-3,1) for the second can you please help. 1. If {{{f(x)=4x^2-3x+2}}}, find f      Log On


   

Question 147158: I need to solve this help solving these two problems, I am stuck I came up with x=2 for the first and (-3,1) for the second can you please help.
1. If f%28x%29=4x%5E2-3x%2B2, find f(-1). I know this is not an equation just simplify.
2. State the domain of f(x)=(x+3)/(x-1)
I would greatly appreciate all the help I can get on these two. I am in College Algebra the text is College Algebra mac2105, Keiser University
Thank you
Teri
Found 2 solutions by nerdybill, mangopeeler07:
Answer by nerdybill(7384) About Me  (Show Source):
You can put this solution on YOUR website!
1. If f(x)=4x^2-3x+2, find f(-1)
All you need to do is replace x with -1 and solve:
f(x)=4x^2-3x+2
f(-1)=4(-1)^2-3(-1)+2
f(-1)=4+3+2
f(-1)=9
.
2. State the domain of f(x)=(x+3)/(x-1)
Domain specifies all values of x for this equation.
The ONLY time this equation will NOT be defined is IF the denominator (x-1) goes to zero.
Therefore, to find where this equation is NOT defined set it to zero and solve:
x-1=0
x = 1
.
From the above,
domain of x is "all real numbers EXCEPT 1"

Answer by mangopeeler07(462) About Me  (Show Source):
You can put this solution on YOUR website!
1. for f(-1) your corresponding range should be 9, because f%28-1%29=4%28-1%5E2%29-3%28-1%29%2B2. so f%28-1%29=4%2B3%2B2. f(-1)=9. That means that when x is -1, y should be 9.
2. f%28x%29=%28x%2B3%29%2F%28x-1%29. Your domain for this problem would be any value for x that does not make the denominator zero. So to figure this out, just take a shortcut and find out what will make the denominator zero, and say that the domain is any value for x except that one. In this case, to make the denominator of %28x%2B3%29%2F%28x-1%29 zero, you would have to ask yourself, what minus one would give me zero? Of course your answer is one, so your domain would be all x except 1.