Question

If f(x) = x − 2 and g(x) = −2x − 3, find (f • g)(6)

Answer 1

If f(x) = −x − 1 and g(x) = 4x − 1, find f[g(−2)]

Answer 2

1) g(6)
g(x)----> -2x -3
= -2(6) -3
= -12 - 3
= -15

for the gf(x) i'm not sure....and i don't wanna give you a wrong answer. :/

Answer 3

what about for this one?

Answer 4

If f(x) = −x − 1 and g(x) = 4x − 1, find f[g(−2)]

Answer 5

If f(x) = x − 4 and g(x) = x − 2, find f[g(−6)].

Answer 6

first one
g(2)= 4x-1
= 4(2) -1
= 8-1
= 7

i will give you another example i did in school:

Given that f:x---> 3-x
g:x---> \[\frac{ x+2 }{ x-5}\]

1) Calculate g(2)
2) State a value of x for which g(x) is not defined.
3) Derive an expression for gf (x)
4) Calculate the value of \[ f{-1}\] (4)

Solution:
1) g(x)----> \[\frac{ x+2 }{ x-5}\]
\[\frac{ 2+2 }{ 2-5 }\]
g(2)= \[\frac{ 4 }{ -3 }\] or -1.33....

2) g(x)---> \[\frac{ x+2 }{ x-5 }\]
\[x-5\neq0\]
\[x \neq5\]

3) g(x): \[\frac{ 1(3-x) +2 }{ 1(3-x)-5 }\]
\[\frac{ 3-x+2 }{ 3-x-5 }\]
=\[\frac{ 3+2-x }{ 3-x-5}\]
= \[\frac{ 5-x }{ -2-x}\]

4) \[f{-1}\] (4)
f(x)-----> 3-x
y= 3-x

5)Interchange x for y
x= 3-y
y=3-x

therefore, \[f{-1}\] (x)= 3-x
\[f{-1}\] (4):
\[f{-1}\] (x) = 3-x
= 3-4
\[f{-1}\] (4) = -1

I hope i didn't confuse you!

Answer 7

thanks helped a lot

Answer 8

your welcome :) try writing it down then reading it because it's confusing with all the spaces!