• Apr 22nd 2009, 05:07 PM
dempc
1. The square root of 2 times (x+the sq root of 8)

the sq root of 2 is outside the parenthesis

My answer = x sq root of 2 + 4

2. Rewrite using a radical then simplify: 8 to the power of 3\5

3. Find the domain and rage of the function f (x) = Sq root of (3x+6)
• Apr 22nd 2009, 06:39 PM
Prove It
Quote:

Originally Posted by dempc
1. The square root of 2 times (x+the sq root of 8)

the sq root of 2 is outside the parenthesis

My answer = x sq root of 2 + 4

2. Rewrite using a radical then simplify: 8 to the power of 3\5

3. Find the domain and rage of the function f (x) = Sq root of (3x+6)

1.
$\sqrt{2}(x + \sqrt{8}) = \sqrt{2}x + \sqrt{2}\sqrt{8}$

$= \sqrt{2}x + 2\sqrt{2}\sqrt{2}$

$= \sqrt{2}x + 4$

2. $8^{\frac{3}{5}} = \sqrt[5]{8^3}$

$= \sqrt[5]{512}$

3. You can only have the square root of a nonnegative number.

So $3x + 6 \geq 0 \implies x \geq -2$

At $x = -2, y = \sqrt{0} = 0$, and y is increasing.

So $\textrm{dom}: x \geq -2, \textrm{ran}: y \geq 0$.