问答题
Functions
These questions will test your knowledge of operations involving functions.
Answer the following questions.
These questions will test your knowledge of operations involving functions.
Answer the following questions.
问答题
| For the function f(x)=x2-4x+8, what is the value of f(6)? |
【正确答案】
【答案解析】To solve, substitute 6 for x in the function:
f(6)=62-4(6)+8
f(6)=36-24+8
f(6)=20
f(6)=62-4(6)+8
f(6)=36-24+8
f(6)=20
问答题
| If f(x)=x2, find f(x+1). |
【正确答案】
【答案解析】To solve, substitute (x+1) for x in the function:
f(x+1)=(x+1)2
(x+1)(x+1)
x2+x+x+1
x2+2x+1
f(x+1)=(x+1)2
(x+1)(x+1)
x2+x+x+1
x2+2x+1
问答题
| If the function f(x)=x+2, and the function g(x)=3x, what is the function g{f(x)}? |
【正确答案】
【答案解析】The problem gives g(x)=3x and f(x)=x+2 and asks for g{f(x)}. The function g{f(x)} means that all of the x values in g(x) are replaced with f(x), as follows:
g{f(x)}=3{f(x)}
g{f(x)}=3(x+2)
g{f(x)}=3x+6
问答题
For the function  what is the value of
f(2)? |
【正确答案】
【答案解析】To solve, substitute 2 for x in the function:
问答题
| For the function f(x)=x2+x, what is the value of f(-5)? |
【正确答案】
【答案解析】To solve, substitute -5 for x in the function:
f(-5)=(-5)2+(-5)
f(-5)=25-5
f(-5)=20
f(-5)=(-5)2+(-5)
f(-5)=25-5
f(-5)=20