Question

Help help needed for composition of function

Answer 1

`\circledast \ \ f\circ f\left( x\right) = x`

`\circledast \ \ g\circ g\left( x\right) =4x - 21`

Explanation:

`f(x)=(5)/(2x)`

g(x) = 2x - 7

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`f\circ f\left( x\right) =(5)/(2\left( f\left( x\right) \right) )`

`=(5)/(2\left( (5)/(2x) \right) )`

`=(5)/(\left( (5)/(x) \right) )`

`=5*(x)/(5)`

`=x`

_____________

`g\circ g\left( x\right) =2(g(x)) - 7`

= 2(2x - 7) - 7

= 4x - 14 - 7

= 4x - 23