Page No 18:
Question 7:
Consider f: R → R given by f(x) = 4x + 3. Show that f is invertible. Find the inverse of f.
f: R → R is given by,
f(x) = 4x + 3
One-one:
Let f(x) = f(y).
∴ f is a one-one function.
Onto:
For y ∈ R, let y = 4x + 3.
Therefore, for any y ∈ R, there exists 
such that
∴ f is onto.
Thus, f is one-one and onto and therefore, f−1 exists.
Let us define g: R→ R by
.
∴
Hence, f is invertible and the inverse of f is given by
