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Single Variable Calculus
Differentiation
01The Derivative as the Slope of the Tangent Line02Secant Lines and the Limit Definition of the Derivative03Differentiating 1/x Straight From the Definition04Tangents to 1/x and the Triangle of Area 205Newton and Leibniz Notation, and the Power RuleProblem set0/10Problem set 20/10MIT problem set0/3
01The Derivative as an Instantaneous Rate of Change02Rates of Change Without Time: Gradient and Sensitivity03Easy Limits, 0/0, and One-Sided Limits04Continuity, Jumps, and Removable Discontinuities05Infinite Discontinuities: 1/x and Its Derivative06Differentiable Implies ContinuousProblem set0/10Problem set 20/10
01Two Kinds of Formula, and the Derivative of Sine02The Derivative of Cosine, and Two Limits at Zero03Bow and Bowstring: Proving the Two Trig Limits04Why the Trig Derivatives Hold Only in Radians05A Geometric Proof: Sine as a Height on the Circle06Finishing the Proof, and the Product and Quotient RulesProblem set0/10Problem set 20/10MIT problem set0/1
01Proving the Product Rule: Change One Factor at a Time02The Quotient Rule, and the Power Rule for Negative Exponents03The Chain Rule: Differentiating a Function of a Function04Higher Derivatives: The Sine Cycle and Three Notations05The nth Derivative of xⁿ Is n Factorial, by InductionProblem set0/10Problem set 20/10MIT problem set0/2
01The Power Rule for Rational Exponents02The Slope of a Circle, Two Ways03Implicit Differentiation of a Quartic Curve04Inverse Functions and the Reflection Across y = x05Derivatives of the Arctangent and ArcsineProblem set0/10Problem set 20/10MIT problem set0/1
01The Derivative of aˣ and the Mystery Number M(a)02Defining e by Slope One, and the Derivative of ln x03M(a) = ln a: Differentiating aˣ and xˣ04Why (1 + 1/n)ⁿ Approaches eProblem set0/10Problem set 20/10MIT problem set0/1
Applications of Differentiation
01Linear Approximation: A Curve Is Its Tangent Line02Five Linear Approximations at Zero03Combining Approximations, from Algebra to GPS Clocks04Quadratic Approximation: The Best-Fit ParabolaProblem set0/10Problem set 20/10MIT problem set0/1
01Linear Approximation as a Proportionality Rule02Quadratic Approximation: Why the ½, and Products03Curve Sketching: The Sign of f′ and Critical Points04Curve Sketching: Ends, Concavity and InflectionProblem set0/10Problem set 20/10MIT problem set0/1
01Sketching Without Critical Points: (x+1)/(x+2)02A Five-Step Curve-Sketching Scheme, Applied to x / ln x03x / ln x: Inflection Point and Where Max and Min Can OccurProblem set0/10Problem set 20/10
01Two Squares From One Wire: The Critical Point Gives the Least Area02The Open Box of Fixed Volume: Least Material When x = 2y03Related Rates: The Police Radar and the Conical TankProblem set0/10Problem set 20/10MIT problem set0/4
01The Hanging Ring: Why the String Makes Equal Angles02Newton's Method: Tangent Lines That Find the Square Root of Five03Why Newton's Method Doubles Its Digits, and How It Fails04The Mean Value Theorem: Somewhere You Hit Your Average Speed05Positive Derivative Means Increasing: Proving eˣ Exceeds 1 + xProblem set0/10Problem set 20/10MIT problem set0/2
Integration
01Differentials: dy = f′(x) dx and the Cube Root of 64.102Antiderivatives Differ Only by a Constant03Integration by Substitution and Advanced GuessingProblem set0/10Problem set 20/10MIT problem set0/1
01Separation of Variables: dy/dx = −xy and the Bell Curve02General Solutions: Signs, Constants and Initial Conditions03Orthogonal Trajectories: Parabolas and Crossing EllipsesProblem set0/10Problem set 20/10MIT problem set0/1
01The Definite Integral: Area as a Limit of Rectangle Sums02Area Under y = x²: Squeezing the Sum of Squares03Sigma Notation and the Area Pattern: b, b²/2, b³/304Riemann Sums: the Definite Integral and a Year of LoansProblem set0/10Problem set 20/10MIT problem set0/1
01The Fundamental Theorem of Calculus: Area in One Line02Net Change and Signed Area: Integrating Velocity03Six Rules for Definite Integrals and Bounds on eᵇ04Substitution in Definite Integrals: Change the LimitsProblem set0/10Problem set 20/10MIT problem set0/1
01Average Rate Times Time: FTC Beats the Mean Value Theorem02Second Fundamental Theorem: Differentiate an Integral03Proving FTC1 and FTC2 with the Mean Value TheoremProblem set0/10Problem set 20/10MIT problem set0/2
Applications of Integration
01The Natural Log Defined as an Area Under 1/t02Functions With No Formula: erf, Fresnel and Li(x)03Setting Up the Area Between Two Curves04Vertical vs Horizontal Slices: One Region, Two IntegralsProblem set0/10Problem set 20/10

Newton and Leibniz Notation, and the Power Rule

How do just two terms of the binomial expansion turn the difference quotient for x^n into the power rule n x^(n-1)?


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Your summary note

    1. 1

      Notations for the derivative

      Record that Δy=Δf\Delta y = \Delta fΔy=Δf so the two difference quotients agree, list f′(x0)f'(x_0)f′(x0​), dfdx\frac{df}{dx}dxdf​, dydx\frac{dy}{dx}dxdy​ and ddxf\frac{d}{dx}fdxd​f as names for the same limit, and note that the Leibniz form drops the base point.

    2. 2

      Binomial expansion needed for (x+Δx)n(x+\Delta x)^n(x+Δx)n

      Write (x+Δx)n=xn+n(Δx)xn−1+O((Δx)2)(x+\Delta x)^n = x^n + n(\Delta x)x^{n-1} + O((\Delta x)^2)(x+Δx)n=xn+n(Δx)xn−1+O((Δx)2) and state where the coefficient nnn and the higher-order junk come from.

    3. 3

      The power rule ddxxn=nxn−1\frac{d}{dx}x^n = nx^{n-1}dxd​xn=nxn−1

      Form the difference quotient for xnx^nxn, cancel xnx^nxn against −xn-x^n−xn, divide by Δx\Delta xΔx to get nxn−1+O(Δx)nx^{n-1} + O(\Delta x)nxn−1+O(Δx), and take the limit as Δx→0\Delta x \to 0Δx→0.

    4. 4

      Extending to polynomials

      State that the rule applies term by term and differentiate one polynomial such as ddx(x3+5x10)=3x2+50x9\frac{d}{dx}(x^3 + 5x^{10}) = 3x^2 + 50x^9dxd​(x3+5x10)=3x2+50x9.

    Attempt 1 of 2