Question

Define a function f : R → R by the formula f(x) = 4x − 8. Prove that f is one-to-one. Let a, b is in R, and suppose that f(a) = f(b). Then 4a − 8 =

Answer 1

it pretty much writes itsefl ...

Answer 2

assume f(a) = f(b)
then 4a-8 = 4b-8
4a=4b
a=b
QED