BeginnerTopic 32 of 104Engineering Mathematics
Integrals
Accumulate quantities such as area, displacement and charge; the reverse of differentiation.
In depth
The integral accumulates a quantity: ∫f dx is the area under f. The indefinite integral gives antiderivatives plus constant C, definite integrals give numbers. Integration finds distance from velocity, charge from current and work from force.
Key points
- Integral of xⁿ = xⁿ⁺¹/(n+1)+C
- Linear in sums and constants
- Area below the axis counts negative
Example∫₀³ 2t dt = 9 m if v=2t m/s.
Integrals accumulate quantities over time or space, so they give charge from current, displacement from velocity and mass from density.
What is Integrals?
Accumulate quantities such as area, displacement and charge; the reverse of differentiation.
Why is it important to understand integrals?
Integrals accumulate quantities over time or space, so they give charge from current, displacement from velocity and mass from density.
What is the difference between an indefinite and a definite integral?
An indefinite integral is a family of antiderivatives with a constant. A definite integral has limits and gives a single number, the net accumulated quantity.
Why do we add a constant of integration?
Any two antiderivatives differ by a constant, so the constant records the initial condition that the problem supplies.
How is Integrals used in practice?
Typical applications include computing the charge that flows through a resistor from a current profile, finding the total energy from a power curve and calculating the area of a cross-section for a volume estimate.
What should I learn before Integrals?
Study "Maxima and minima" first (topic 31 of 104 in Engineering Mathematics). It covers the groundwork this topic builds on.
What are the key points of Integrals?
Integral of xⁿ = xⁿ⁺¹/(n+1)+C. Linear in sums and constants. Area below the axis counts negative.
Can you give an example of Integrals?
∫₀³ 2t dt = 9 m if v=2t m/s.
What comes after Integrals?
The next topic is "Fundamental theorem of calculus", which builds directly on this one.
How difficult is Integrals?
It is classed as Beginner in Engineering Mathematics (topic 32 of 104). It is an entry-level topic. It relies only on basic school mathematics and the ideas introduced earlier in this discipline.