f(x) = 5x + 11 / 4
g(x) = 4x - 5 / 11

i need to evaluate f(g(x)) and based upon the solution state wether the functions are inverse, would help gratefuly! only bit im really struggling on! wathed vids on u tube and read about 10 books but dont understand, even is someone points me in the right direction, ive tried swapping the x with a number to see if there inverse but i donth think they are, any help gratefully appreciated

Barry

2. In f(g(x)), g(x) acts as a variable.
$f(g(x)) = 5g(x)+\frac{11}{4}$
$f(g(x)) = 5(4x-\frac{5}{11})+\frac{11}{4}$
If $f(x)=g^{-1}(x) \implies g(x)=f^{-1}(x)$ and $f(g(x))=g(f(x))=x$

3. Originally Posted by barrypan83
f(x) = 5x + 11 / 4
g(x) = 4x - 5 / 11

i need to evaluate f(g(x))
did you mean ...

$f(x) = \frac{5x+11}{4}$ and $g(x) = \frac{4x-5}{11}$ ?

4. Originally Posted by barrypan83
f(x) = 5x + 11 / 4
g(x) = 4x - 5 / 11

i need to evaluate f(g(x)) and based upon the solution state wether the functions are inverse, would help gratefuly! only bit im really struggling on! wathed vids on u tube and read about 10 books but dont understand, even is someone points me in the right direction, ive tried swapping the x with a number to see if there inverse but i donth think they are, any help gratefully appreciated

Barry
If you mean f(x)= (5x+11)/4 and g(x)= (4x- 5)/11, then $f(g(x))= (5g(x)+ 11)/4= \frac{5(\frac{4x-5}{11})+ 11}{4}= \frac{\frac{20x- 25}{11}+ 11}{4}$= $\frac{20x- 25+ 121}{44}= \frac{20x+ 96}{44}= \frac{5x+ 24}{11}$