Functions as a Unifying Language: mastery answer key

In this solving $f(x)=k$ case, change one numerical value, solve the revised problem, and identify which parts of the original method still apply: For $f(x) = x^{2} - 5x + 4,$ solve $f(x) = 4$.

Write a complete attempt before opening the response guide.

Connect the opening situation “Use a horizontal target line on a graph.” to the algebraic structure used in the worked case. Define quantities and units before writing any equation.

Write a complete attempt before opening the response guide.

Explain why the method for solving $f(x)=k$ is valid here and name one nearby problem where it would not apply.

Write a complete attempt before opening the response guide.

Compare the conclusions of all three worked cases with this lesson outcome—Find every input that produces a requested output. Explain what remains invariant across them.

Write a complete attempt before opening the response guide.

Exit check: solve and verify without referring to the displayed steps. For $f(x) = x^{2} - 4x - 5,$ solve $f(x) = 7$.

Write a complete attempt before opening the response guide.

Exit check: solve and verify without referring to the displayed steps. For $g(x) = \frac{3}{x - 1},$ solve $g(x) = -2$.

Write a complete attempt before opening the response guide.

Classify the mathematical object and requested action in this lesson case: Find the real domain of $g(x) = \frac{\sqrt{2x - 6}}{x - 5}$.

Write a complete attempt before opening the response guide.

State the central definition behind this outcome: Determine allowed inputs from context, denominators, and even roots.

Write a complete attempt before opening the response guide.

Before calculating, list every sign, endpoint, unit, grouping, or domain condition that can affect: Find the real domain of $g(x) = \frac{\sqrt{2x - 6}}{x - 5}$.

Write a complete attempt before opening the response guide.

Explain why this opening move is valid: Require the even-root radicand $2x - 6$ to be nonnegative.

Write a complete attempt before opening the response guide.

Find the real domain of$$g(x) = \frac{\sqrt{2x - 6}}{x - 5}$$

Write a complete attempt before opening the response guide.

Find the real domain of$$f(x) = \frac{\sqrt{5 - 2x}}{x + 3}$$

Write a complete attempt before opening the response guide.

Find the domain of$$h(x) = \frac{1}{\sqrt{x^{2} - 9}}$$

Write a complete attempt before opening the response guide.

Verify the proposed result “$[3, 5)$ ∪ $(5,$ ∞).” against the original statement.

Write a complete attempt before opening the response guide.

Complete the calculation after “Require the radicand $5 - 2x \ge 0,$ giving $\frac{x \le 5}{2}$.” in this problem: Find the real domain of $f(x) = \frac{\sqrt{5 - 2x}}{x + 3}$.

Write a complete attempt before opening the response guide.

Name and justify the most efficient first move, then solve: Find the domain of $h(x) = \frac{1}{\sqrt{x^{2} - 9}}$.

Write a complete attempt before opening the response guide.

Compare the methods used in these two cases and identify the structural reason they differ: Find the real domain of $f(x) = \frac{\sqrt{5 - 2x}}{x + 3}$. Find the domain of $h(x) = \frac{1}{\sqrt{x^{2} - 9}}$.

Write a complete attempt before opening the response guide.

Create the representation most useful for checking this result: Find the real domain of $f(x) = \frac{\sqrt{5 - 2x}}{x + 3}$. Use a mapping or table, a formula with domain, and a graph that passes the vertical-line test.

Write a complete attempt before opening the response guide.