Question

let f (x) = 4/x^2 + 5 ... g (x) = Sqrt x

find f o g and g o f.

Answer 1

fog = f((g)) = 4x + 5
gof = g((f)) = Sqrt(4x^2+5)

Answer 2

where is sqrt gone in function f o g ?

Answer 3

hmm 'cux (Sqrtx)^2 = x right??

Answer 4

You mean we canceled out sqrt with ^2 ? and please also explain the procedure how we can do it.

Answer 5

yep fog mean that you put g(x) in stead of x in f(x)
so x in f(x) should change into Sqrtx
get it?

Answer 6

and also where is division sign has gone ?

Answer 7

oh nooo it's not gone I just saw it wrong lol

Answer 8

it should be 4/x + 5 then

Answer 9

yea, thnx and 2nd one?

Answer 10

Sqrt(4/x^2+5)

Answer 11

in 2nd one every value is included in sqrt , right?

Answer 12

yupp

Answer 13

\[fog(x)=\frac4x+5\]
\[gof(x)=\sqrt{\frac{4}{x^2}+5}\]

Answer 14

thnx cinar