Questions: Graph the function with a graphing calculator. Then, visually estimate the domain and the range.
f(x) = sqrt(19-x)
Graph the function f(x) = sqrt(19-x) with a graphing calculator. Choose the correct graph below.
A.
[-30,30,-10,10]
B.
[-30,30,-10,10]
C.
[-10,40,-10,10]
D.
[-40,10,-10,10]
Transcript text: Graph the function with a graphing calculator. Then, visually estimate the domain and the range.
\[
f(x)=\sqrt{19-x}
\]
Graph the function $f(x)=\sqrt{19-x}$ with a graphing calculator. Choose the correct graph below.
A.
$[-30,30,-10,10]$
B.
$[-30,30,-10,10]$
C.
\[
[-10,40,-10,10]
\]
D.
$[-40,10,-10,10]$
Solution
Solution Steps
Step 1: Analyze the function
The function \(f(x) = \sqrt{19 - x}\) is a square root function. The value inside the square root must be non-negative.
Step 2: Determine the domain
The domain of the function is the set of all possible x-values for which the function is defined. Since the expression inside the square root must be greater than or equal to zero, we have \(19 - x \ge 0\). This simplifies to \(x \le 19\). So, the domain is \((-\infty, 19]\).
Step 3: Determine the range
Since the square root function always returns a non-negative value, the smallest value of \(f(x)\) is 0, which occurs when \(x = 19\). As x decreases, \(19 - x\) increases, and so does \(\sqrt{19 - x}\). Therefore, the range is \([0, \infty)\).
Step 4: Choose the correct graph
The graph should start at \(x = 19\) and extend to the left. Option B is the correct graph because it depicts a square root function that starts at \(x = 19\) and decreases as x decreases. Options C and D depict increasing functions, and option A is an increasing square root function that starts at the origin. Option B matches the expected graph with the domain ending at \(x = 19\). The given window of [-30, 30, -10, 10] is not the best viewing window, but the general shape of the graph is correct.
Final Answer
The correct graph is B. The domain is \(\boxed{(-\infty, 19]}\) and the range is \(\boxed{[0, \infty)}\).