Question

Show that the function given by f(x) = 3x + 17 is strictly increasing on R.

Answer 1

Let x₁ and x₂ be any two numbers in R.
Then, we have:

Hence, f is strictly increasing on R.

Alternate method:
f'(x) = 3 > 0, in every interval of R.
Thus, the function is strictly increasing on R.