📚 Key Concepts
Quadratic Formula: x = (−b ± √(b²−4ac)) / (2a)
Discriminant: Δ = b² − 4ac
Δ > 0 → 2 real roots | Δ = 0 → 1 real root (double) | Δ < 0 → 2 complex roots
Axis of symmetry: x = −b / (2a)
∴ x = 2 or x = 3
📚 Key Concepts
The Factor Theorem: (x − a) is a factor of p(x) if and only if p(a) = 0.
End behavior: determined by the degree and leading coefficient sign.
Degree n polynomial has AT MOST n real roots and exactly n complex roots (counted with multiplicity).
If (x − r) appears an even number of times, the graph TOUCHES the x-axis at r but doesn't cross.
∴ Remainder = 9
📚 Key Concepts
Horizontal Asymptote: compare degrees of numerator (n) and denominator (m)
• n < m → y = 0 | n = m → y = (leading coeff ratio) | n > m → no H.A. (slant instead)
A hole occurs when a factor cancels from both numerator and denominator.
To find a hole: set the canceled factor = 0, then find the y-value by plugging x into the simplified function.
After canceling (x + 2): simplified = 1/(x − 2), hole at x = −2
Vertical asymptote: x = 2 only
📚 Key Concepts
Complex: a + bi | Conjugate: a − bi
|a + bi| = √(a² + b²)
To divide complex numbers, multiply numerator AND denominator by the conjugate of the denominator.
To find iⁿ: divide n by 4 and use the remainder (0→1, 1→i, 2→−1, 3→−i).
i³ = −i ∴ i²⁷ = −i
📚 Key Concepts
logₐ(m/n) = logₐm − logₐn
logₐ(mⁿ) = n·logₐm
Change of base: logₐb = ln(b)/ln(a) = log(b)/log(a)
logₐ(aˣ) = x and aˡᵒᵍₐˣ = x (inverse property)
ln(e) = 1 | ln(1) = 0 | log(10) = 1 | log(1) = 0
So 2ˣ⁺¹ = 2⁴ → x + 1 = 4 → x = 3
📚 Key Concepts
Geometric: aₙ = a₁·rⁿ⁻¹ | Sₙ = a₁(1−rⁿ)/(1−r) for r ≠ 1
Infinite geometric sum: S∞ = a₁/(1−r) when |r| < 1
An infinite geometric series converges ONLY when |r| < 1.
Common ratio r = aₙ₊₁ / aₙ (any consecutive terms).
S∞ = 8 / (1 − 1/2) = 8 / (1/2) = 16
📚 Key Concepts
1 + tan²θ = sec²θ | 1 + cot²θ = csc²θ
Amplitude = |a|, Period = 2π/|b| for y = a·sin(bx + c) + d
sin(30°) = 1/2 | cos(60°) = 1/2 | sin(45°) = cos(45°) = √2/2
sin(60°) = cos(30°) = √3/2 | sin(90°) = 1 | cos(0°) = 1
(Amplitude = 3, phase shift = π/2 to the right)
📚 Key Concepts
Ellipse: (x−h)²/a² + (y−k)²/b² = 1 (a > b > 0, horizontal major axis)
Hyperbola: (x−h)²/a² − (y−k)²/b² = 1 (opens left/right)
Parabola: (x−h)² = 4p(y−k) where p = distance from vertex to focus
Ellipse: c² = a² − b² (a > b) | Hyperbola: c² = a² + b²
Eccentricity: circle e=0, ellipse 0<e<1, parabola e=1, hyperbola e>1
📚 Key Concepts
det(A) = ad − bc
A⁻¹ = (1/det(A)) · [[d,−b],[−c,a]] (only if det(A) ≠ 0)
Matrix multiplication AB is defined only when columns of A = rows of B.
AB ≠ BA in general (matrix multiplication is NOT commutative).
A system Ax = b has unique solution iff det(A) ≠ 0.
📚 Key Concepts
Combinations: C(n,r) = n! / (r!(n−r)!)
Binomial Theorem: (a+b)ⁿ = Σ C(n,k)·aⁿ⁻ᵏ·bᵏ for k=0 to n
Permutation = ORDER matters (P for Position).
Combination = ORDER does NOT matter (C for Choose).
The (k+1)th term in (a+b)ⁿ expansion = C(n,k)·aⁿ⁻ᵏ·bᵏ