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Essential Math Formulas for Digital SAT

May 2, 2025

Digital SAT Math Formula Bible

Overview

  • Essential video for preparing for the digital SAT math section.
  • Contains critical concepts and formulas.
  • Includes reference to a recommended SAT crash course with a discount code.

Key Formulas and Concepts

Reference Sheet Formulas

  • Accessible during both math modules
    • Area and circumference of a circle.
    • Conversions between radians and degrees.
    • Sum of angles in a triangle.
    • Volume formulas.
    • Special right triangles.

Slope and Linear Equations

  1. Slope Formula

    • Slope ( m = \frac{y_2 - y_1}{x_2 - x_1} )
    • Example: Coordinates (7, 2) and (5, 1) gives slope ( \frac{1}{2} )
  2. Slope-Intercept Form

    • Equation: ( y = mx + b )
    • Example: ( y = 2x + 7 ) with slope 2 and y-intercept 7
  3. Point-Slope Form

    • Formula: ( y - y_1 = m(x - x_1) )
    • Example: ( y - 4 = 3(x - 3) )

Midpoint and Distance

  1. Midpoint Formula

    • Formula: ( \left( \frac{x_1 + x_2}{2}, \frac{y_1 + y_2}{2} \right) )
    • Example: Midpoint of (8, 4) and (6, 7) is (7, 5.5)
  2. Distance Formula

    • Formula: ( \sqrt{(x_2 - x_1)^2 + (y_2 - y_1)^2} )
    • Example: Distance between (5, 3) and (1, 0) is 5

Circle Formulas

  1. Length of an Arc

    • Formula: ( \frac{n}{360} \times 2\pi r )
  2. Area of a Sector

    • Formula: ( \frac{n}{360} \times \pi r^2 )
  3. Circle Equation

    • Formula: ( (x - h)^2 + (y - k)^2 = r^2 )
    • Example: Center (2, -5), radius 6

Quadratic and Exponential Functions

  1. Quadratic Formula

    • Formula: ( x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} )
  2. Exponential Growth & Decay

    • Formula: ( y = a(1 \pm r)^t )
    • Growth Example: Initial 200, growth rate 13%, 3 years

Trigonometry

  1. SOHCAHTOA

    • Sine, Cosine, and Tangent definitions
  2. Complementary Angles in Trigonometry

    • ( \sin(\theta) = \cos(90^\circ - \theta) )

Probability and Rational Functions

  1. Probability

    • Formula: ( \frac{\text{favorable outcomes}}{\text{total outcomes}} )
  2. Rational Functions

    • Graph characteristics: x-intercepts, vertical asymptotes, y-intercepts

Triangle Concepts

  1. Pythagorean Theorem

    • Formula: ( a^2 + b^2 = c^2 )
  2. Special Right Triangles

    • 45-45-90 and 30-60-90 triangles
  3. Triangle Congruence and Similarity Theorems

    • Congruence: SSS, SAS, ASA, AAS, HL
    • Similarity: AA, SAS, SSS

Miscellaneous Formulas

  1. Distance = Rate × Time

  2. Sum and Product of Roots of Quadratics

    • Sum: ( -\frac{b}{a} )
    • Product: ( \frac{c}{a} )
  3. Exponent Rules

    • Multiplication, division, zero exponent, etc.
  4. Foiling and Binomials

    • FOIL method and squaring binomials
  5. Inequalities

    • Flip inequality sign when dividing/multiplying by a negative number.

Conclusion

  • Knowing these formulas and concepts is crucial for tackling the digital SAT math section.
  • Recommended to practice using these concepts with practice tests and review sessions.