Let `f"":""NvecY` be a function defined as `f""(x)""=""4x""+""3` , where `Y""=""{y in N"":""y""=""4x""+""3` for some `x in N}` . Show that f is invertible and its inverse is (1) `g(y)=(3y+4)/3` (2) `g(y)=4+(y+3)/4` (3) `g(y)=(y+3)/4` (4) `g(y)=(y-3)/4`

Explanation

`f(x)=4x+3`

`Rightarrowy=4x+3`

inverse of f is

`Rightarrowy−3=4x`
`
Rightarrow(y−3)/4`
`
=x`
`
therefore x=g(y) `
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therefore g(y)=4(y−3) `
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