Equations to Put in Calculator for Sat

Preparing for the SAT math section requires knowing which equations to put in your calculator. This guide covers essential equations, proper calculator usage, and tips to maximize your score.

Basic Equations

The SAT math section tests your ability to work with basic equations. Here are the most common ones you'll need to put in your calculator:

Quadratic Formula

For equations of the form ax² + bx + c = 0:

x = [-b ± √(b² - 4ac)] / (2a)

Distance Formula

For two points (x₁, y₁) and (x₂, y₂):

Distance = √[(x₂ - x₁)² + (y₂ - y₁)²]

Slope Formula

For two points (x₁, y₁) and (x₂, y₂):

Slope (m) = (y₂ - y₁) / (x₂ - x₁)

Algebra Equations

Algebra is a significant part of the SAT math section. These equations are essential for solving algebra problems:

Quadratic Mean

For a set of numbers x₁, x₂, ..., xₙ:

Quadratic Mean = √[(x₁² + x₂² + ... + xₙ²) / n]

Arithmetic Mean

For a set of numbers x₁, x₂, ..., xₙ:

Arithmetic Mean = (x₁ + x₂ + ... + xₙ) / n

Geometric Mean

For a set of numbers x₁, x₂, ..., xₙ:

Geometric Mean = (x₁ × x₂ × ... × xₙ)^(1/n)

Geometry Equations

Geometry problems on the SAT often require calculations. Here are key formulas:

Area of a Circle

A = πr²

Volume of a Sphere

V = (4/3)πr³

Pythagorean Theorem

a² + b² = c²

Trigonometry Equations

Trigonometry appears in both the no-calculator and calculator sections. These are the most important formulas:

Sine Rule

a / sin A = b / sin B = c / sin C

Cosine Rule

c² = a² + b² - 2ab cos C

Unit Circle Values

sin(0) = 0, cos(0) = 1, tan(0) = 0

sin(π/2) = 1, cos(π/2) = 0, tan(π/2) = undefined

Calculator Tips

Using your calculator effectively can save you time and improve your accuracy:

Always check if the problem requires a calculator before starting
Use the calculator's memory functions to store intermediate results
Double-check your inputs before calculating
Round final answers to the nearest hundredth when required
Verify your answer makes sense in the context of the problem

Remember: The SAT calculator is not a scientific calculator. It only has basic functions like addition, subtraction, multiplication, division, exponents, and square roots.

FAQ

What equations should I memorize for the SAT?

Focus on the quadratic formula, distance formula, slope formula, quadratic mean, arithmetic mean, geometric mean, area of a circle, volume of a sphere, Pythagorean theorem, sine rule, cosine rule, and unit circle values. These cover most of the calculator-based problems.

Can I use my phone's calculator for the SAT?

No, the SAT provides a calculator. You must use the one provided during the test. It's a basic four-function calculator with square roots and exponents.

How do I know when to use the calculator?

The SAT test booklet indicates when a calculator is allowed. Look for the calculator icon next to the section number. Only use the calculator for problems marked with this icon.

What if I make a mistake on the calculator?

If you realize you've made a mistake, press the "AC" button to clear the calculator and start over. Don't try to backspace or correct individual digits.

Can I use the calculator for all math sections?

No, the calculator is only allowed for the "Calculator" sections. The "No Calculator" sections require you to solve problems without any computational aids.