Difference between revisions of "2006 Cyprus MO/Lyceum/Problem 3"

Latest revision as of 10:50, 27 April 2008

The domain of the function $f(x)=\sqrt{4+2x}$ is

$\mathrm{(A)}\ (-2,+\infty)\qquad\mathrm{(B)}\ [0,+\infty)\qquad\mathrm{(C)}\ [-2,+\infty)\qquad\mathrm{(D)}\ [-2,0]\qquad\mathrm{(E)}\ \mathbb{R}$

$2x+4$ must be non-negative, so $x+2$ must be non-negative. Therefore, all $x\ge-2$ are in the domain $\mathrm{(C)}$ .

@@ Line 5: / Line 5: @@
 ==Solution==
-<math>2x+4</math> must be non-negative, so <math>x+2</math> must be non-negative.
+<math>2x+4</math> must be non-negative, so <math>x+2</math> must be non-negative. Therefore, all <math>x\ge-2</math> are in the domain <math>\mathrm{(C)}</math>.
-Therefore, all <math>x\ge-2</math> are in the domain <math>\mathrm{(C)}</math>.
 ==See also==
 {{CYMO box|year=2006|l=Lyceum|num-b=2|num-a=4}}