Question

Let $I$ be an open interval contained in the domain of a real function $f$, then $f\left(x\right)$ is called strictly increasing function in $I$ if

• A. $x_1>x_2$ in $I=f\left(x_1\right)>f\left(x_2\right)$
• B. $x_1<x_2$ in $I=f\left(x_1\right)>f\left(x_2\right)$
• C. $x_1=x_2$ in $I=f\left(x_1\right)=f\left(x_2\right)$
• D. $x_1=x_2$ in $I=f\left(x_1\right)<f\left(x_2\right)$

Answer 1

The correct option is A $x_1>x_2$ in $I=f\left(x_1\right)>f\left(x_2\right)$

Basic definition of increasing function
If $x_1>x_2$ & $f\left(x_1\right)>f\left(x_2\right)$ than function is increasing in given Interval.