SATMediumFrequency: 1 - 2 questions
Desmos Regression & Line of Best Fit Shortcuts
The built-in Desmos calculator allows you to find equations through points using regression: enter table values into x1 and y1, then type y1 ~ mx1 + b for linear or y1 ~ ax1² + bx1 + c for quadratic. Desmos calculates m and b instantly.
Core Formula & Concept Cheat Sheet
1Linear regression in Desmos: y1 ~ mx1 + b
2Quadratic regression in Desmos: y1 ~ ax1^2 + bx1 + c
3Residual = Observed - Predicted
Desmos Speed-Run Trick
Click '+' icon -> Table. Input points from the problem. In line 2, write y1 ~ mx1 + b to get exact slope and y-intercept immediately.
The 700+ Score Trap
Confusing the sign of residuals (positive residual means point lies above the best fit line).
Test Your Mastery
Official Exam FormatLive Interactive Practice Drill
A line in the xy-plane passes through points (-3, 14) and (5, -10). What is the y-intercept of the line?
Frequently Asked Questions
Can regression be used for three points on a parabola?
Yes! Enter the 3 points into a table, then run y1 ~ ax1^2 + bx1 + c to find coefficients a, b, and c without manual substitution.