⭐ High-Yield Formulas NOT Provided on the SAT (Must Memorize)
These formulas appear on over 60% of medium-to-hard Digital SAT Math questions, but College Board does not give them on the reference sheet:
| Concept / Topic | Formula & Mathematical Expression | Key Takeaway & Exam Trap |
|---|---|---|
| Vertex Form (Parabolas) | y = a(x - h)² + k |
Vertex is at (h, k). If a > 0, k is minimum. If a < 0, k is maximum. |
| Vertex from Standard Form | x_vertex = -b / (2a) |
Plug x_vertex back into equation to find the maximum/minimum y value. |
| Sum and Product of Roots | Sum = -b / a • Product = c / a |
Finds root sum in 5 seconds without factoring or using the quadratic formula. |
| Quadratic Discriminant | D = b² - 4ac |
D > 0: 2 real solutionsD = 0: 1 real solutionD < 0: 0 real solutions |
| Circle Standard Form | (x - h)² + (y - k)² = r² |
Center is (h, k), radius is r = √r². Watch for the sign reversal! |
| Exponential Growth & Decay | y = a(1 ± r)ᵗ |
a = initial amount; r = growth/decay rate as decimal; t = number of time periods. |
| Slope & Linear Equations | m = (y₂ - y₁) / (x₂ - x₁) |
Parallel lines have equal slope (m₁ = m₂). Perpendicular lines have negative reciprocal slopes (m₁ · m₂ = -1). |
| Complementary Angles (Trig) | sin(x°) = cos(90° - x°) |
If sin(A) = cos(B), then A + B = 90°. Tested constantly on the SAT! |