Question: Which of the following functions is strictly decreasing for $\displaystyle x\in\Re$? (a)$\displaystyle f(x)=x^2$ (b)$\displaystyle f(x)=-x$ (c)$\displaystyle f(x)=\sqrt{x}$ (d)$\displaystyle f(x)=2-x^2$
Follow Math Help Forum on Facebook and Google+
Originally Posted by ibnashraf Question: Which of the following functions is strictly decreasing for $\displaystyle x\in\Re$? (a)$\displaystyle f(x)=x^2$ (b)$\displaystyle f(x)=-x$ (c)$\displaystyle f(x)=\sqrt{x}$ (d)$\displaystyle f(x)=2-x^2$ did you look at the graphs of these functions?
The answer is (b), $\displaystyle 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...
View Tag Cloud