Calculus: Integrals · Grades 1212

Integrals Worksheets

Indefinite integrals of polynomials using the reverse power rule, with the constant of integration, built from clean antiderivatives so every answer is an exact whole-number expression.

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What it is

Integration reverses differentiation. To integrate a term with the power rule, increase its exponent by 1 and divide by the new exponent. Since any constant's derivative is 0, every indefinite integral includes '+ C' for the unknown constant.

Why it matters

Integration is the second core operation of calculus alongside differentiation, and understanding it as the REVERSE of differentiation (rather than a brand new unrelated skill) is the single most useful mental model for learning it quickly.

How to do it

  1. For each term, add 1 to the exponent.
  2. Divide the coefficient by the new exponent.
  3. Add '+ C' at the end to represent any possible constant term.

Examples by level

  • Beginner∫ (6) dx =6x + C
  • Intermediate∫ (−6) dx =−6x + C
  • Advanced∫ (−27x² + 12x − 2) dx =−9x³ + 6x² − 2x + C

Examples are generated by the same engine as the worksheets, so they're always mathematically correct. Built to avoid repeats, not reshuffle the same handful of questions.

Common mistakes

  • Forgetting to add '+ C' at the end of every indefinite integral.
  • Multiplying by the new exponent instead of dividing by it.
  • Applying the power rule incorrectly to a constant term (a lone number integrates to that number times x, not to itself).

Tips

  • Integration is the reverse operation of differentiation, if you're unsure of an answer, differentiate it and check you get back the original problem.
  • Never forget the '+ C': without it, the answer is incomplete, since any constant could have been there before differentiating.

For parents

If your child already knows derivatives, frame integration as 'working backward', differentiate their answer and check it matches the original problem.

For teachers

This deliberately covers indefinite integrals of polynomials only, mirroring how derivatives.ts scopes to the power rule alone, definite integrals and other integration techniques are a natural next skill, not this one.

Key vocabulary

antiderivative
a function whose derivative is the given function; what you find when you integrate
constant of integration (C)
the unknown constant added to every indefinite integral, since constants disappear when differentiated

Frequently asked questions

What grade are integrals taught in?
Integrals typically follow derivatives in a Grade 12 introductory calculus course.
Why is '+ C' always needed?
Because the derivative of any constant is 0, infinitely many antiderivatives differ only by a constant, '+ C' represents all of them at once.

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