Graph the function. Compare to the parent graph. State the domain and range.

$\mathit{y}\mathbf{=}\sqrt{\mathbf{x}\mathbf{+}\mathbf{4}}$

Parent graph:The simplest form of the given function is called the parent function of that function and the graph of the parent function is called the parent graph.

Domain: The set of all possible values for which a given function is defined is called domain.

Range: The set of all possible values of the given function is called range.

The given function is: $y=\sqrt{x+4}$

To graph a function, find a few coordinates by substituting values of ‘$x$’ and find finding the respective values of ‘$y$’.

$\begin{array}{c}\text{For\hspace{0.17em}\hspace{0.17em}}x=-4,\\ y=\sqrt{-2+4}\\ =\sqrt{0}\\ =0\end{array}$

$\begin{array}{c}\text{For\hspace{0.17em}\hspace{0.17em}}x=-3,\\ y=\sqrt{-3+4}\\ =\sqrt{1}\\ =1\end{array}$

$\begin{array}{c}\text{For\hspace{0.17em}\hspace{0.17em}}x=0,\\ y=\sqrt{0+4}\\ =\sqrt{4}\\ =2\end{array}$

$\begin{array}{c}\text{For\hspace{0.17em}\hspace{0.17em}}x=5,\\ y=\sqrt{5+4}\\ =\sqrt{9}\\ =3\end{array}$

$\begin{array}{c}\text{For\hspace{0.17em}\hspace{0.17em}}x=12,\\ y=\sqrt{12+4}\\ =\sqrt{16}\\ =4\end{array}$

Plot these coordinates on a coordinate plane and join those points to get the required graph.

The parent function $y=\sqrt{x+4}$is the simplest square root function.

That is, $y=\sqrt{x}$

The graph of the parent function$y=\sqrt{x}$is given below.

Note: Since the parent function is just used for comparison, it is graphed using the graphing calculator.

The value 4 is added inside the square root of the parent function $y=\sqrt{x}$. So the graph$y=\sqrt{x+4}$ is the translation of the parent graph $y=\sqrt{x}$.

Since 4 is added inside the root, the graph is translated to the left by 4 units.

Since the values inside the root must be positive.

$x+4\ge 0$

Adding ‘$-4$’ on both sides.

$\begin{array}{c}x+4-4\ge 0-4\\ x+0\ge -4\\ x\ge -4\end{array}$

$x\ge -4\Rightarrow x\in [-4,\infty )$

Therefore, domain: $[-4,\infty )$

The $y$values are $\sqrt{x+4}$. As square roots are positive,$y$takes all the positive real values including zero.

Therefore,$y\ge 0,\Rightarrow y\in [0,\infty )$

Therefore, Range:$[0,\infty )$