Dabour Hub EGEgyptian Curriculum 2026/2027
3-3 (a) The definite integral and the fundamental theorem of calculus

3-3 (a) The definite integral and the fundamental theorem of calculus

Point 7 of 12 — Lesson 1: Integration Techniques (Substitution and By Parts) and Definite IntegralsQuestion bank: 14 questions (9 with pictures)

07 3-3 (a) The definite integral and the fundamental theorem of calculus

Meaning

  • The indefinite integral contains an arbitrary constant, so it does not give a definite number.
  • The difference between its values at x=b and x=a does not depend on the constant: (F(b)+c)−(F(a)+c)=F(b)−F(a)
  • This number is the definite integral.

Fundamental theorem of calculus

  • If f is continuous on [a,b] and F is any antiderivative of f on [a,b]: ∫abf(x) dx=F(b)−F(a)=[F(x)]ab
  • a and b are the lower and upper limits of the integral.
  • The value is a real number that depends only on f, a and b; the name of the variable does not matter: ∫abf(x) dx=∫abf(t) dt.
  • You may drop the constant c when evaluating, because it cancels in F(b)−F(a).
  • Every rule of indefinite integration and every standard integral still applies.
  • A continuous function on [a,b] is integrable on [a,b].
Point of comparison Indefinite integral Definite integral
Result A family of functions F(x)+c One real number
Constant c Present Not needed
Limits None Lower a and upper b
✍️ Worked examples

Example 14: Find ∫−24(3x2−2) dx.

Solution:

  • f is a continuous polynomial.
  • ∫−24(3x2−2) dx=[x3−2x]−24.
  • =(64−8)−(−8+4).
  • =56+4=60.

📝 Question bank for this point

14 questions linked to this point only, 9 of them with pictures.