# Question #8471c

Dec 31, 2014

The original powers of the 2 brackets are $\frac{1}{2}$ i.e. square roots. You can still see them when you open the question. For some reason they appear as ones!

#### Explanation:

$2 \le x \le 4$

Your function is the sum of two square roots. Your square roots cannot have negative argument (you cannot find a real number which is solution of a negative square root).
So you must avoid negative arguments; so it must be:
$2 x - 4 \ge 0$ and (at the same time) $- 5 x + 20 \ge 0$

The first gives you: $x \ge 2$
The second gives you: $x \le 4$
BUT, they have to work together in your function!

The shaded region ($2 \le x \le 4$) is where your function can accept values of $x$.