Given f(x) = x², describe g(x) = 2(x−3)² + 1
→ Right 3, Up 1, Vertical stretch ×2
Vertex moves from (0,0) → (3, 1)
1
Easy
Which transformation maps f(x) = √x to g(x) = √(x+4) − 2?
#transformation
Inside the function: (x+4) means shift LEFT 4 (opposite sign!).
Outside: −2 means shift DOWN 2. KEY: Inside = opposite direction. Outside = same direction.
2
Tricky!
If f(x) = x² and g(x) = f(−x), which statement is TRUE?
#reflection
f(−x) reflects over the y-axis. But f(−x) = (−x)² = x² = f(x).
So g(x) = f(x) — the parabola is symmetric, they look identical! KEY: Even functions satisfy f(−x) = f(x) → y-axis symmetry.
3
Medium
The domain of h(x) = √(5 − 2x) is:
#domain
Square roots need radicand ≥ 0.
5 − 2x ≥ 0 → 5 ≥ 2x → x ≤ 5/2 = 2.5 KEY: √(expression) → set expression ≥ 0, solve for x.
🔢Section 2 — Polynomials & Rational Functions
"ZERO-FAR" = Zeros · End behavior · Factored form · Asymptotes · Remainder theorem
Rational Root Test: possible roots = ±(factors of constant) / (factors of leading coeff)
End behavior of f(x) = −3x⁴ + 2x − 1:
Even degree + Negative leading → BOTH ends go DOWN ↓↓ Remember: look at the LEADING TERM only!
4
Easy
What is the remainder when p(x) = x³ − 4x + 6 is divided by (x − 2)?
#remainder-theorem
Remainder Theorem: remainder = p(2)
p(2) = (2)³ − 4(2) + 6 = 8 − 8 + 6 = 6 KEY: Divide by (x−a) → plug in x = a to get remainder instantly!
5
Tricky!
The rational function r(x) = (x² − 9) / (x² − x − 6) has a hole (removable discontinuity) at x =
#rational-functions
Factor: (x²−9) = (x+3)(x−3) and (x²−x−6) = (x−3)(x+2)
Common factor (x−3) cancels → hole at x = 3
Remaining denominator (x+2) → vertical asymptote at x = −2 KEY: HOLE = canceled factor. ASYMPTOTE = remaining denominator = 0.
6
Medium
How many positive real zeros can f(x) = x⁴ − 3x³ + x² + x − 2 have, according to Descartes' Rule?
#Descartes-rule
Sign changes in f(x): +, −, +, +, −
Changes at positions: +→−, −→+, +→− = 3 sign changes
→ Possible positive zeros: 3 or 1 (subtract 2 each time) KEY: Count sign changes in f(x). That's max positive zeros. Reduce by 2 for other possibilities.
🔵Section 3 — Trigonometry
"ASTC" = All · Sin · Tan · Cos (which are positive per quadrant I→IV)
"All Students Take Calculus" 🎓 | Unit circle: memorize 0°, 30°, 45°, 60°, 90°
Period of y = 3sin(2x − π) + 1:
A = 3 (amplitude) · B = 2 · Period = 2π/B = 2π/2 = π
Phase shift = π/2 to the RIGHT · Midline: y = 1
7
Easy
In what quadrant is the angle θ if sin θ < 0 and cos θ > 0?
#ASTC #quadrants
cos > 0 → right side → Quadrant I or IV
sin < 0 → below x-axis → Quadrant III or IV
Intersection: Quadrant IV ✓ KEY: ASTC — QI: all +, QII: sin+, QIII: tan+, QIV: cos+
8
Medium
What is the period of f(x) = tan(3x)?
#period #tangent
Period of tan(bx) = π/b (NOT 2π/b like sine/cosine!)
Period = π/3 KEY: sin/cos period = 2π/b · tan/cot period = π/b (half as long!)
9
Tricky!
Simplify: (sin²x − 1) / cos x#identities
sin²x − 1 = −(1 − sin²x) = −cos²x (Pythagorean identity)
So: −cos²x / cos x = −cos x ✓ KEY: When you see (sin²x ± 1), think Pythagorean identity: sin²+cos²=1
What is the center and radius of (x+3)² + (y−5)² = 49?
#circle
Standard form: (x−h)²+(y−k)² = r²
(x−(−3))² + (y−5)² = 49 → h = −3, k = 5, r = √49 = 7 KEY: Signs flip! (x+3) means h = −3 · (y−5) means k = 5 · r = √(right side)
15
Tricky!
The equation 4x² − 9y² = 36 represents which conic?
#conics #identification
Divide by 36: x²/9 − y²/4 = 1
This is x²/a² − y²/b² = 1 → Hyperbola, x-axis transverse (opens left/right) ✓ KEY: Both squared? Same sign→ellipse/circle, Different sign→hyperbola. One squared→parabola.
16
Medium
The foci of ellipse x²/25 + y²/9 = 1 are at:
#ellipse #foci
a² = 25, b² = 9 (a > b, so major axis is x-axis)
c² = a² − b² = 25 − 9 = 16 → c = 4
Foci on x-axis: (±4, 0) ✓ KEY: c² = a² − b² for ellipse. Foci go along major axis (bigger denominator wins).
🔗Section 6 — Sequences, Systems & Miscellaneous
"SAG" = Sum formula · Arithmetic (add d) · Geometric (multiply r)
Arithmetic Sₙ = n/2·(a₁+aₙ) · Geometric Sₙ = a₁(1−rⁿ)/(1−r) · Infinite Geo S = a₁/(1−r) only if |r|<1
17
Medium
The sum of the infinite geometric series 4 + 2 + 1 + ½ + ... is:
#infinite-series #geometric
r = 2/4 = 1/2 (|r| < 1 so sum exists ✓)
S∞ = a₁/(1−r) = 4/(1−½) = 4/(½) = 8 ✓ KEY: Infinite geo sum works ONLY if |r| < 1. Formula: S = first term ÷ (1 − ratio)
18
Tricky!
Using the binomial theorem, the coefficient of x³y² in the expansion of (x + y)⁵ is:
#binomial-theorem