1. General form of the equation of a circle: x² + y² + Dx + Ey + F = 0 (where D, E, and F are constants)
2. Distance between two points in a plane: d = √((x₂ - x₁)² + (y₂ - y₁)²)
3. Midpoint formula: M = ((x₁ + x₂) / 2, (y₁ + y₂) / 2)
4. Slope of a line passing through points (x₁, y₁) and (x₂, y₂): m = (y₂ - y₁) / (x₂ - x₁)
5. Equation of a line in slope-intercept form: y = mx + c (where m is the slope and c is the y-intercept)
6. Equation of a line in point-slope form: y - y₁ = m(x - x₁)
7. General form of a line equation: Ax + By + C = 0
8. Distance from a point to a line: d = |Ax₁ + By₁ + C| / √(A² + B²) (where (x₁, y₁) is the point and Ax + By + C = 0 is the line)
9. Volume of a regular tetrahedron: V = (√2 / 12) a³ (where a is the side length)
10. Surface area of a regular tetrahedron: SA = √3 a² (where a is the side length)
11. Volume of an octahedron: V = (√2 / 3) a³ (where a is the side length)
12. Surface area of an octahedron: SA = 2√3 a² (where a is the side length)
13. Volume of a regular dodecahedron: V = (15 + 7√5) / 4 a³ (where a is the side length)
14. Surface area of a regular dodecahedron: SA = 3√25 + 10√5 a² (where a is the side length)
15. Volume of a regular icosahedron: V = 5(3 + √5) / 12 a³ (where a is the side length)
16. Surface area of a regular icosahedron: SA = 5√3 a² (where a is the side length)
17. Polar to Cartesian coordinates: x = r cos(θ), y = r sin(θ)
18. Cartesian to Polar coordinates: r = √(x² + y²), θ = tan⁻¹(y / x)
19. Polar form of the equation of a line: r = l / cos(θ - φ) (where l is the perpendicular distance from the origin and φ is the angle with the positive x-axis)
20. Polar form of the equation of a circle: r(θ) = R (where R is the radius)
21. Parametric equations for a circle in polar coordinates: x = R cos(θ), y = R sin(θ) (where R is the radius and θ is the parameter)
22. Magnitude of a vector in 3D: |A| = √(A₁² + A₂² + A₃²)
23. Scalar projection of vector A onto vector B: proj_B(A) = (A · B) / |B|
24. Vector projection of vector A onto vector B: Proj_B(A) = ((A · B) / |B|²) B
25. Angle between two vectors: cos(θ) = (A · B) / (|A||B|)
26. Cross product: A × B = (A₂B₃ - A₃B₂)i + (A₃B₁ - A₁B₃)j + (A₁B₂ - A₂B₁)k
27. Dot product: A · B = A₁B₁ + A₂B₂ + A₃B₃
28. Product-to-Sum Formulas:
- sin(A) sin(B) = ½ [cos(A - B) - cos(A + B)]
- cos(A) cos(B) = ½ [cos(A + B) + cos(A - B)]
- sin(A) cos(B) = ½ [sin(A + B) + sin(A - B)]
29. Sum-to-Product Formulas:
- sin(A) ± sin(B) = 2 sin((A ± B) / 2) cos((A ∓ B) / 2)
- cos(A) + cos(B) = 2 cos((A + B) / 2) cos((A - B) / 2)
- cos(A) - cos(B) = -2 sin((A + B) / 2) sin((A - B) / 2)
30. Half-Angle Formulas:
- sin²(A/2) = (1 - cosA) / 2
- cos²(A/2) = (1 + cosA) / 2
- tan²(A/2) = (1 - cosA) / (1 + cosA)
31. Double Angle Formulas:
- sin(2A) = 2 sinA cosA
- cos(2A) = cos²A - sin²A = 2 cos²A - 1 = 1 - 2 sin²A
- tan(2A) = 2 tanA / (1 - tan²A)
32. Triple Angle Formulas:
- sin(3A) = 3 sinA - 4 sin³A
- cos(3A) = 4 cos³A - 3 cosA
- tan(3A) = (3 tanA - tan³A) / (1 - 3 tan²A)
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