Functions and Relations: Solving for f, g, and h

[nae99]

If f(x)= 2x+5, g(x)=0.5 and h(x)=3-1
find:
fg(x), gf(x), fh(3)


fg(x)
fg(x)= 2(0.5x)+5
fg(x)= x+5


gf(x)= 0.5(2x+5)
= x+2.5


fh(3)
fh (x) =2(3-1)+5
= 6-2+5
= 4+5


this last part of the question been puzzling me... could I get a little help pleasezz

 

[Dick]

If f(x)= 2x+5, g(x)=0.5 and h(x)=3-1
find:
fg(x), gf(x), fh(3)fg(x)
fg(x)= 2(0.5x)+5
fg(x)= x+5gf(x)= 0.5(2x+5)
= x+2.5fh(3)
fh (x) =2(3-1)+5
= 6-2+5
= 4+5 this last part of the question been puzzling me... could I get a little help pleasezz

I'm going to guess from your solution you meant g(x)=0.5*x. If you really meant h(x)=3-1 then the last one is fine. But writing h(x)=3-1 is a little odd. Why not just write h(x)=2, or is it another typo?

 

[eumyang]

If f(x)= 2x+5, g(x)=0.5 and h(x)=3-1
find:
fg(x), gf(x), fh(3)

Isn't the notation wrong? It looks like you want
[itex](f \circ g)(x)[/itex], [itex](g \circ f)(x)[/itex] and [itex](f \circ h)(x)[/itex]
(function composition)
but it looks more like
[itex](fg)(x)[/itex], [itex](gf)(x)[/itex] and [itex](fh)(x)[/itex]
(combining functions by multiplication)