Teaching calculators

Solver apps paywall their steps and never explain which method to pick. These tools do the opposite: the method is the product, and it is free.

• Riemann Sum Visualizer: Rectangles, Error, and Rules

  Enter a function, interval, and n, then watch left, right, midpoint, and trapezoidal rectangles build a definite-integral estimate and see the exact error.

• Chain Rule Step Trainer: You Pick the Decomposition

  Practice the hard part of the chain rule: pick the outer and inner function, then watch the derivative assemble step by step. AP Calculus Topic 3.1.

• U-Substitution Helper: Pick u, See Why It Works

  Practice choosing u for u-substitution. Pick a candidate, watch the tool compute du and rewrite the integral, and get a hint when a choice fails.

• Series Convergence Test Chooser: Which Test and Why (BC)BC

  Walk the convergence decision tree test by test: nth-term, geometric, p-series, alternating, ratio, comparison, integral, and see why each one fits or fails.

• Limit Solver (Teaching Mode): Which Method and Why

  See which method each AP Calculus limit needs and why: direct substitution, factoring, conjugates, trig limits, or L'Hopital, chosen by the form you get.

• Definite Integral Step Tool: FTC, Shown Honestly

  The Fundamental Theorem of Calculus in three honest steps: find an antiderivative, evaluate at both bounds, subtract. What FTC evaluation really means.

• Tangent and Normal Line Finder (Teaching Mode)

  Find the tangent and normal line to any curve: compute f'(x), evaluate the slope at your point, and build both equations with point-slope form. AP Topic 2.2.

• Taylor Series Builder: Coefficients from DerivativesBC

  Pick a function, a center, and a degree, then watch each derivative turn into a coefficient and the Taylor polynomial close in on the curve. AP Calculus BC.

• Derivative Practice Checker: Any Correct Form Passes

  Type each function's derivative and get graded by numeric equivalence: any algebraically equal form counts. Rule hints on a miss, full derivation on request.

• Related Rates Setup Builder: The Five-Step Method

  Set up any related rates problem in five steps: name the quantities, pick the relation, differentiate with respect to time, then solve. AP Topics 4.4, 4.5.

• Optimization Setup Builder: Objective vs Constraint

  Set up AP Calculus optimization problems: separate the objective from the constraint, reduce to one variable, state the domain, and justify the max or min.

• Interval of Convergence Finder: Ratio Test and EndpointsBC

  Find a power series interval of convergence: the ratio test gives the radius, then test each endpoint on its own. AP Calculus BC, Topic 10.13.