Desmos Calculator Mastery • Lesson 5 of 7
Regression Tools
Let the calculator find the line of best fit through a set of data points.
When a question gives data points and asks for a line (or curve) of best fit, Desmos finds it for you. Put the data in a table as x_1 and y_1, then type a model with a tilde: y_1 ~ m x_1 + b. The calculator reports the best m and b; plug an x into that equation to predict, or read the slope’s meaning in context. A quadratic fit is y_1 ~ a x_1^2 + b x_1 + c.
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Predictions are trustworthy only within the range of the data. Extending a fit far beyond the points (extrapolation) is unreliable.
Vidaara’s calculator focuses on graphing and scientific calculation; for full regression practice, use the official Desmos tool, but the setup — data in a table, then a tilde model — is exactly as described here.
Formula Reference Sheet
This chapter
Fast moves
| Solve f(x)=0 | graph y=f(x); turn on key points |
|---|---|
| Solve an equation | graph both sides; read where they meet |
| Evaluate | use the Scientific tab |
Digital SAT reference
Area & Circumference
| Circle area | A = πr² |
|---|---|
| Circle circumference | C = 2πr |
| Rectangle | A = ℓw |
| Triangle | A = ½ b h |
Volume
| Rectangular box | V = ℓwh |
|---|---|
| Cylinder | V = πr²h |
| Sphere | V = 4⁄3 πr³ |
| Cone | V = 1⁄3 πr²h |
| Pyramid | V = 1⁄3 ℓwh |
Right triangles
| Pythagorean theorem | a² + b² = c² |
|---|---|
| 30°–60°–90° | sides x : x√3 : 2x |
| 45°–45°–90° | sides s : s : s√2 |
Constants
| Degrees in a circle | 360° |
|---|---|
| Radians in a circle | 2π |
| Angles of a triangle | sum = 180° |
🖩 Graphing Calculator