Show that the function f (x) = 2x + 3 is strictly increasing function on R.

Asked by Topperlearning User | 6th Aug, 2014, 08:00: AM

Expert Answer:

Let x­1, x2 Î R and let x1 < x2

Then,

x1 < x2

Þ 2x1 < 2x2

Þ 2x1 + 3 < 2x2 + 3

Þ f (x1) < f (x2)

Thus, x1 < x2 Þ f (x1) < f (x2) for all x1, x2 Î R.

So, f (x) is strictly increasing function on R.

Answered by  | 6th Aug, 2014, 10:00: AM