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Linear Functions, Tables, and Models

SAT MathAlgebraMedium

Interpret function notation and build linear rules from patterns.

What you need to know

  • f(x) names the output produced by input x.
  • A constant first difference for equal x-steps indicates a linear function.
  • Initial value is the output at input 0.
  • A context determines meaningful domain and range.

The AYLOTI method

  1. Find change in output over change in input.
  2. Use one row or point to determine the intercept.
  3. Write f(x) = mx + b.
  4. Check the rule against another value and interpret parameters.

AYLOTI • Sir Hunain Zia • SAT Score 1594/1600 • 154 Total A Grades (Personal), 11 World Records, 7 Distinctions

Worked example

A table contains (0, 7), (2, 13), and (5, 22). Find f(x).

  1. Slope from first two points: (13 − 7)/(2 − 0) = 3.
  2. At x = 0, output is 7, so b = 7.
  3. Rule: f(x) = 3x + 7; it gives 22 at x = 5.

Answer: f(x) = 3x + 7.

Common SAT traps

  • Using Δx/Δy instead of Δy/Δx.
  • Assuming the first listed output is the intercept when x ≠ 0.
  • Ignoring a restricted contextual domain.
Quick check

If f(x) = 5x − 4, find f(3).

11.

Before you move on

  • Explain the core rule without looking back.
  • Redo the worked example using your own steps.
  • Write the trap you are most likely to fall for.
Hunain Zia

Hunain Zia has previously achieved considerable success in the high-school educational stream, gaining a massive 154 Total A Grades and 7 Major Distinctions, a process in which he broke/ set 11 different world records, including the most A grades ever achieved, most subjects ever appeared in, most distinctions, gaining distinctions across two separate boards (Pearson Edexcel and CAIE) within the same year/ ever, and even 19 hours of constant examination. All records stand intact today. Hunain pursued his Honors Accounting Degree from the prestigious Bentley University, and then completed an LLB (in Honors) from University of London. Currently, he manages multiple social and commercial projects, has founded digital streams and works tirelessly in the education sector.

Educate A Change focuses on truly bringing change in the educational sector worldwide. All our courses are designed to ensure success, and provide complete preparation without requiring any other external material. Therefore, it takes away the expense of academies, books, past paper compilations and other miscellaneous items. Instead, by just the courses we offer, the student can prepare fully for the best grades in their CAIEs, Edexcel and other high-school exams. The earnings from our course-sales are invested in social projects and growing the free educational activities of Educate A Change.

Linear Functions, Tables, and Models

SAT MathAlgebraMedium

Interpret function notation and build linear rules from patterns.

What you need to know

  • f(x) names the output produced by input x.
  • A constant first difference for equal x-steps indicates a linear function.
  • Initial value is the output at input 0.
  • A context determines meaningful domain and range.

The AYLOTI method

  1. Find change in output over change in input.
  2. Use one row or point to determine the intercept.
  3. Write f(x) = mx + b.
  4. Check the rule against another value and interpret parameters.

AYLOTI • Sir Hunain Zia • SAT Score 1594/1600 • 154 Total A Grades (Personal), 11 World Records, 7 Distinctions

Worked example

A table contains (0, 7), (2, 13), and (5, 22). Find f(x).

  1. Slope from first two points: (13 − 7)/(2 − 0) = 3.
  2. At x = 0, output is 7, so b = 7.
  3. Rule: f(x) = 3x + 7; it gives 22 at x = 5.

Answer: f(x) = 3x + 7.

Common SAT traps

  • Using Δx/Δy instead of Δy/Δx.
  • Assuming the first listed output is the intercept when x ≠ 0.
  • Ignoring a restricted contextual domain.
Quick check

If f(x) = 5x − 4, find f(3).

11.

Before you move on

  • Explain the core rule without looking back.
  • Redo the worked example using your own steps.
  • Write the trap you are most likely to fall for.
Hunain Zia

Hunain Zia has previously achieved considerable success in the high-school educational stream, gaining a massive 154 Total A Grades and 7 Major Distinctions, a process in which he broke/ set 11 different world records, including the most A grades ever achieved, most subjects ever appeared in, most distinctions, gaining distinctions across two separate boards (Pearson Edexcel and CAIE) within the same year/ ever, and even 19 hours of constant examination. All records stand intact today. Hunain pursued his Honors Accounting Degree from the prestigious Bentley University, and then completed an LLB (in Honors) from University of London. Currently, he manages multiple social and commercial projects, has founded digital streams and works tirelessly in the education sector.

Educate A Change focuses on truly bringing change in the educational sector worldwide. All our courses are designed to ensure success, and provide complete preparation without requiring any other external material. Therefore, it takes away the expense of academies, books, past paper compilations and other miscellaneous items. Instead, by just the courses we offer, the student can prepare fully for the best grades in their CAIEs, Edexcel and other high-school exams. The earnings from our course-sales are invested in social projects and growing the free educational activities of Educate A Change.