Calculate: g:Y→N
Given: f(x)=4x+3
Let f(x)=y
y=4x+3
4x=y−3
x=y−34
Let g(y)=y−34 where g:Y→N
Solve to prove gof=IN.
gof=g(f(x))
⇒gof=g(4x+3)
⇒gof=(4x+3)−34
⇒gof=4x4=x=IN...(1)
Solve to prove fog=Iy.
fog=f(g(x))
⇒fog=f(y−34)
⇒fog=4(y−34)+3
⇒fog=y−3+3
⇒fog=y=Iy...(2)
From (1) and (2)
gof=IN and fog=Iy
⇒f is invertible, so
Inverse of f=g(y)=y−34