Integration Made Easy
By Masood Amir
Calculus:
Calculus is a tool used to measure change or variation of a function with respect to the independent variable.
Differential Calculus:
It is the branch of calculus used to measure change or variation of a function in a very small interval of time, the techniques use to measure such changes is called “differentiation”.
Integral Calculus:
It is the branch of calculus used to measure changes or variation over an interval of independent variable, e.g to find length of curve, the area of region and the volume of a solid in a specified period of time.
The technique used to measure such changes or variation is called “Integration” or “Antiderivatives”. It a reverse process of differentiation.
Mathematically, Integration is defined as “ If f’(x) represents the differential coefficient of f(x), then the problem of integration is given f’(x), find f(x) or given dy/dx, find y.
Notation: ”∫ ” is used to show the integration, it is a symbol of “S” derived from the word “Sum”. i.e. Integration is a process in which we have to sum up the derivatives over a specified interval and to find the function.
Techniques of Integration:
As we know that integration is the reverse process of differentiation, our problem is to find the function f(x) or Y, when f’(X) or dy/dx is given.
dy/dx = f’(X)
∫dy = ∫f ’(X)dx
Y= f(x) is our solution
Ist Formula of Integration (1st Rule of Integration)
Indefinite Integration:
Ist Formula of Integration (Ist Rule of Integration):
If y = xn
∫ dy = ∫ xndx
y = xn+1/n+1 + C
Why “C”:
In the process of differentiation, we eliminate constant, as the derivative of a constant is “zero”.
So, In functions like Xn, Xn+ 6, Xn + 3 , Xn – K, the derivatives of all of them is Xn-1, in finding the anti derivative of Xn-1, we put a constant “C”, as we don’t know which constant was present in the original function, and this can be found If we have initial boundary values (Definite Integral).
Example: Solve ∫x3dx
Solution: x3+1/3+1 + C = x4/4 + C
Example: Solve ∫(x3 + x2 + 5x + 6)dx
Solution: ∫x3dx + ∫x2dx + ∫5xdx + ∫6dx
X4/4 + x3/3 + 5x2/2+ 6x + C
Worksheet # 1
Find the Integral of the following:
SET 1
a. ∫(x3-4x2+5x-6)dx
- ∫(3x5-4x3+3x2)dx
c. ∫(ax5-bx4)dx
- ∫(x3/2-5x4/3+3x2)dx
e.∫(4√3x2 -2x)dx
- ∫(3x + 5x2 –x3/2-0.4x4)dx
g. ∫(x(8x-1/2)dx
- ∫(2-x)(4+3x)dx
- ∫(x-3 + x-4)dx
- ∫(2x3-3)3x4dx
k. ∫(4x7 + 3x12 -5x8 + 2x -1)dx
- ∫(ax3 – bx2 + cx –d)dx
- ∫(1/x3 + 2/x2 -6)dx
- ∫(-3x-8 + 2√x)dx
- ∫((x3 -5)(2x + 5)dx
- ∫(7x-6 + 5√x)dx
More Questions
Evaluate ∫ (2x + 3) dx.
Answer: x^2 + 3x + C,
Find ∫ (5e^x + 2x) dx.
Answer: 5e^x + x^2 + C,
Calculate ∫ (3sin(x) + 4cos(x)) dx.
Answer: -3cos(x) + 4sin(x) + C,
Evaluate ∫ (4x^3 – 2x^2 + 5) dx.
Answer: x^4/4 – 2x^3/3 + 5x + C,
Find ∫ (6/x) dx.
Answer: 6ln|x| + C,
Calculate ∫ (2sec^2(x)) dx.
Answer: 2tan(x) + C,
Evaluate ∫ (3e^(2x) + 2/x) dx.
Answer: (3/2)e^(2x) + 2ln|x| + C,
Find ∫ (4sinh(x) + 2cosh(x)) dx.
Answer: 4cosh(x) + 2sinh(x) + C,
Calculate ∫ (2x^2 – 3x + 1) dx.
Answer: (2/3)x^3 – (3/2)x^2 + x + C,
Evaluate ∫ (7x^2 + 6x + 5) dx.
Answer: (7/3)x^3 + 3x^2 + 5x + C,
Find ∫ (2sec(x)tan(x)) dx.
Answer: 2sec(x) + C,
Calculate ∫ (e^x + 1/x^2) dx.
Answer: e^x – 1/x + C, where C is the constant of integration.
Evaluate ∫ (2cos(3x) – 3sin(2x)) dx.
Answer: (2/3)sin(3x) + (3/2)cos(2x) + C, where C is the constant of integration.
Find ∫ (5x^4 + 4x^3 + 3x^2) dx.
Answer: (5/5)x^5 + (4/4)x^4 + (3/3)x^3 + C, where C is the constant of integration.
Calculate ∫ (2/(x+1)) dx.
Answer: 2ln|x+1| + C, where C is the constant of integration.
Evaluate ∫ (6e^(2x) + 2/x^3) dx.
Answer: (3e^(2x) – 1/x^2) + C, where C is the constant of integration.
Find ∫ (3cosec^2(x)cot(x)) dx.
Answer: -3cosec(x) + C,
Calculate ∫ (x^2 + √x + 1) dx.
Answer: (1/3)x^3 + (2/3)x^(3/2) + x + C,
Evaluate ∫ (4sin(3x) + 3cos(4x)) dx.
Answer: -(4/3)cos(3x) + (3/4)sin(4x) + C,
Find ∫ (5x^3 – 2x^2 + 1/x) dx.
Answer: (5/4)x^4 – (2/3)x^3 + ln|x| + C,
Calculate ∫ (2/(x^2 + 4x + 5)) dx.
Answer: 2arctan(x + 2) + C,
Evaluate ∫ (e^x – e^(-x)) dx.
Answer: e^x + e^(-x) + C,
Find ∫ (2x^3 – 3x^2 + 4x – 5) dx.
Answer: (2/4)x^4 – (3/3)x^3 + 2x^2 – 5x + C,
Calculate ∫ (3/x^2) dx.
Answer: -3/x + C,
Evaluate ∫ (6sin(x)cos(x)) dx.
Answer: 3sin^2(x) + C,
Find ∫ (x^2 + 2x + 3) dx.
Answer: (1/3)x^3 + x^2 + 3x + C,
Calculate ∫ (3e^(2x) – 2e^(-x)) dx.
Answer: (3/2)e^(2x) + 2e^(-x) + C,
Evaluate ∫ (4x + 5) dx.
Answer: 2x^2 + 5x + C,
Find ∫ (6tan(x)sec^2(x)) dx.
Answer: 6tan(x) + C,
Calculate ∫ (1/(x^2 + 9)) dx.
Answer: (1/3)arctan(x/3) + C,
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