Systematic problem-solving approaches to master calculus concepts through daily practice.
Read carefully, identify what's being asked
Choose strategy, recall relevant formulas
Solve step-by-step with clear work
Check answer, test limits, verify units
Review mistakes, note patterns, improve
Common problem types:
Integration approaches:
Key techniques:
ε-δ proofs, infinite limits, continuity
All rules, implicit, logarithmic diff
Optimization, related rates, tangent lines
Techniques, FTC, area between curves
Convergence, power series, Taylor
Partial derivatives, gradients, chain rule
AP-style problems, timed practice
Let x = distance from wall, y = height on wall, dx/dt = 1 ft/s
Step 2: Relate variablesBy Pythagorean theorem: x² + y² = 10²
Step 3: Differentiate2x·dx/dt + 2y·dy/dt = 0
Step 4: Solve for dy/dtWhen x = 6, y = √(100-36) = 8
2(6)(1) + 2(8)·dy/dt = 0
dy/dt = -12/16 = -0.75 ft/s
Step 5: InterpretNegative means sliding down at 0.75 ft/s
Product of polynomial (x) and exponential (e^(2x)) → Integration by parts
Step 2: Choose u and dvu = x (polynomial simplifies when differentiated)
dv = e^(2x) dx (exponential easy to integrate)
Step 3: Apply formula∫ u dv = uv - ∫ v du
du = dx, v = (1/2)e^(2x)
Step 4: Compute∫ x·e^(2x) dx = x·(1/2)e^(2x) - ∫ (1/2)e^(2x) dx
= (1/2)x·e^(2x) - (1/4)e^(2x) + C
= (1/4)e^(2x)(2x - 1) + C
Step 5: VerifyDifferentiate result to check: d/dx[(1/4)e^(2x)(2x-1)] = x·e^(2x) ✓
limₓ→₀ sin(θ)/θ = 1
Rewrite: (sin(3x))/(5x) = (3/5)·(sin(3x))/(3x)
Let u = 3x, as x→0, u→0
= (3/5)·limᵤ→₀ sin(u)/u = (3/5)·1 = 3/5
Method 2: L'Hôpital's RuleForm: 0/0 as x→0
Derivative of numerator: 3cos(3x)
Derivative of denominator: 5
limₓ→₀ (3cos(3x))/5 = 3cos(0)/5 = 3/5
Key Insight:Both methods confirm answer. Use known limits when possible (faster).