Let , where is a real constant. Which one of the following describes the monotonic…

MATHEMATICS · Single correct · AP · Calculus AB · Analytical Applications of Differentiation · Analytical Applications of Differentiation

Problem

Let

f(x)=kx+7

, where

k

is a real constant. Which one of the following describes the monotonic behaviour of

f

\mathbb R

? (a)

f

is strictly increasing if

k\ge 0

and strictly decreasing if

k<0

. (b)

f

is strictly increasing if

k<0

and strictly decreasing if

k>0

. (c)

f

is strictly increasing if

k>0

and strictly decreasing if

k<0

. (d)

f

is strictly increasing for every

k\neq 0