# strictly decreasing

• December 9th 2009, 02:50 PM
ibnashraf
strictly decreasing
Question: Which of the following functions is strictly decreasing for $x\in\Re$?

(a) $f(x)=x^2$

(b) $f(x)=-x$

(c) $f(x)=\sqrt{x}$

(d) $f(x)=2-x^2$
• December 9th 2009, 03:03 PM
skeeter
Quote:

Originally Posted by ibnashraf
Question: Which of the following functions is strictly decreasing for $x\in\Re$?

(a) $f(x)=x^2$

(b) $f(x)=-x$

(c) $f(x)=\sqrt{x}$

(d) $f(x)=2-x^2$

did you look at the graphs of these functions?
• December 9th 2009, 06:35 PM
millerst
The answer is (b), $f(x)=-x$... but if you don't understand this I think you need to invest time into understanding the graphs and what it means to have a decreasing function...