Exercise 7.5
Integrate the functions in Exercises 1 to 21.
Solun:- Let f(x) =
Integrate f(x):-
By partial Fraction:-
⇒ x = A(x+2) + B(x+1) …....(1)
Put x = -2 in eq. 1:-
⇒ -2 = 0 + B(-1)
⇒ B = 2
Put x = -1 in eq. 1:-
⇒ -1 = A(1)
⇒ A = -1 then
We know that:-
We know that:-
n.log m = log mn
log m - log n = log (m/n)
Solun:- Let f(x) =
Integrate f(x):-
By partial Fraction:-
⇒ 1 = A(x + 3) + B(x - 3) …....(1)
Put x = 3 in eq. 1:-
⇒ 1 = A(6)
⇒ A = 1/6
Put x = -3 in eq. 1:-
⇒ 1 = B(-6)
⇒ B = -1/6 then
We know that:-
We know that:-
log m - log n = log (m/n)
Solun:- Let f(x) =
Integrate f(x):-
By partial Fraction:-
⇒ 3x - 1 = A(x-2)(x-3) + B(x-3)(x-1) + A(x-1)(x-2) …....(1)
Put x = 1 in eq. 1:-
⇒ 2 = A(-1)(-2) + 0 + 0
⇒ A = 1
Put x = 2 in eq. 1:-
⇒ 5 = B(-1)(1)
⇒ B = -5
Put x = 3 in eq. 1:-
⇒ 8 = C(2)(1)
⇒ C = 4 then
We know that:-
We know that:-
n.log m = log mn
Solun:- Let f(x) =
Integrate f(x):-
By partial Fraction:-
⇒ x = A(x-2)(x-3) + B(x-3)(x-1) + A(x-1)(x-2) …....(1)
Put x = 1 in eq. 1:-
⇒ 1 = A(-1)(-2) + 0 + 0
⇒ A = 1/2
Put x = 2 in eq. 1:-
⇒ 2 = B(-1)(1)
⇒ B = -2
Put x = 3 in eq. 1:-
⇒ 3 = C(2)(1)
⇒ C = 3/2 then
We know that:-
Solun:- Let f(x) =
Integrate f(x):-
By partial Fraction:-
⇒ 2x = A(x+2) + B(x+1)
Put x = -1 in eq. 1:-
⇒ -2 = A(1)
⇒ A = -2
Put x = -2 in eq. 1:-
⇒ -4 = B(-1)
⇒ B = 4 then
We know that:-
Solun:- Let f(x) =
Integrate f(x):-
The power of the numerator is equal to the denominator then
By quotient rule:-
By partial Fraction:-
⇒ 2 - x = A(1 - 2x) + B(x)
Put x = 0 in eq. 1:-
⇒ 2 = A(1)
⇒ A = 2
Put x = 1/2 in eq. 1:-
⇒ 3/2 = B(1/2)
⇒ B = 3 then
We know that:-
Solun:- Let f(x) =
Integrate f(x):-
By partial Fraction:-
⇒ x = (Ax+B)(x - 1) + C(x2 + 1).......(1)
Put x = 1 in eq. 1:-
⇒ 1 = C(2)
⇒ C = 1/2
Put x = 0 in eq. 1:-
⇒ 0 = B(-1)+C
⇒ B = C = 1/2
Put x = -1 in eq. 1:-
⇒ -1 = (-A+B)(-2)+C(2)
⇒ -1 = (-A+½)(-2)+(½)(2)
⇒ -1 = 2A-1+1
⇒ -1 = 2A
⇒ A = -1/2 then
Calculate I1:-
Let x2 + 1 = t
⇒ 2x.dx = dt
⇒ x.dx = (1/2).dt
We know that:-
Put the value of t:-
Calculate I2:-
We know that:-
Calculate I3:-
Solun:- Let f(x) =
Integrate f(x):-
By partial Fraction:-
⇒ x = A(x - 1)(x + 2) + B(x + 2) + C(x - 1)2…....(1)
Put x = 1 in eq. 1:-
⇒ 1 = B(3)
⇒ B = 1/3
Put x = - 2 in eq. 1:-
⇒ - 2 = C(9)
⇒ C = -2/9
Put x = 0 in eq. 1:-
⇒ 0 = A(-2) + B(2) + C(1)
⇒ 0 = A(-2) +(2/3) + (-2/9)
⇒ 0 = A(-2) +(4/9)
⇒ A = 2/9 then
We know that:-
Solun:- Let f(x) =
Integrate f(x):-
By partial Fraction:-
⇒ 3x + 5 = A(x - 1)(x + 1) + B(x + 1) + C(x - 1)2…....(1)
Put x = 1 in eq. 1:-
⇒ 8 = 2B
⇒ B = 4
Put x = - 1 in eq. 1:-
⇒ 2 = 4C
⇒ C = 1/2
Put x = 0 in eq. 1:-
⇒ 5 = A(-1) + B(1) + C(1)
⇒ 5 = A(-1) + 4(1) +(1/2)
⇒ A = -1/2 then
We know that:-
We know that
⇒ log m - log n = log (m/n)
Solun:- Let f(x) =
Integrate f(x):-
By partial Fraction:-
⇒ 2x - 3 = A(x + 1)(2x + 3) + B(x - 1)(2x + 3) + C(x - 1)(x + 1)
Put x = 1:-
⇒ -1 = A(2)(5)
⇒ A = -1/10
Put x = - 1:-
⇒ -5 = B(-2)(1)
⇒ B = 5/2
Put x = -3/2:-
⇒ -6 = C(-5/2)(-1/2)
⇒ C = -24/5 then
We know that:-
Solun:- Let f(x) =
Integrate f(x):-
By partial Fraction:-
⇒ 5x = A(x - 2)(x + 2) + B(x + 1)(x + 2) + C(x + 1)(x - 2)
Put x = -1:-
⇒ -5 = A(-3)(1)
⇒ A = 5/3
Put x = 2:-
⇒ 10 = B(3)(4)
⇒ B = 10/12 = 5/6
Put x = -2 in eq. 1:-
⇒ -10 = C(-1)(-4)
⇒ C = -10/4 = -5/2 then
We know that:-
Solun:- Let f(x) =
Integrate f(x):-
The power of the numerator is greater than the denominator.
By quotient rule:-
Let x2 - 1 = t
Differentiate w.r.t. to t:-
2x.dx = dt
We know that:-
Put the value of t:-
We know that:-
log (m.n) = log m + log n
log (m/n) = log m - log n
Solun:- Let f(x) =
Integrate f(x):-
By partial Fraction:-
⇒ 2 = A(1 + x2) + (Bx+C)(1 - x)
Put x = 1:-
⇒ 2 = A(2)
⇒ A = 1
Put x = 0:-
⇒ 2 = A(1) + C(1)
⇒ 2 =(1) + C(1)
⇒ C = 1
Put x = -1:-
⇒ 2 = A(2) + (-B+C)(2)
⇒ 1 = A - B + C
⇒ 1 = 1 - B + 1
⇒ B = 1 then
Let 1 + x2 = t
Differentiate w.r.t. to t:-
2x.dx = dt
x.dx = (1/2).dt
We know that:-
Put the value of t:-
Solun:- Let f(x) =
Integrate f(x):-
By partial Fraction:-
⇒ 3x - 1 = A(x + 2) + B
Put x = - 2:-
⇒ - 7 = B
⇒ B = -7
Put x = 0:-
⇒ -1 = A(2) + B
⇒ -1 = A(2) - 7
⇒ 2A = 6
⇒ A = 3 then
We know that:-
Solun:- Let f(x) =
Integrate f(x):-
By partial Fraction:-
⇒ 1 = A(x + 1)(x2 + 1) + B(x-1)(x2 + 1) + (Cx+D)(x - 1)(x + 1)
Put x = 1:-
⇒ 1 = A(2)(2)
⇒ A = 1/4
Put x = - 1:-
⇒ 1 = B(-2)(2)
⇒ B = -1/4
Put x = 0:-
⇒ 1 = A(1)(1) + B(-1)(1) + D(-1)(1)
⇒ 1 = (1/4) +(-1)(-1/4) + D(-1)(1)
⇒ 1 = (2/4) + D(-1)(1)
⇒ D = -1/2
Put x = 2:-
⇒ 1 = A(3)(5) + (-1/4)(1)(5) + (2C-1/2)(1)(3)
⇒ 1 = (15/4) +(-5/4) + 6C - 3/2
⇒ C = 0 then
We know that:-
Put the value of t:-
Solun:- Let f(x) =
Integrate f(x):-
Let xn + 1 = t
Differentiate w.r.t. to t:-
⇒ nxn-1dx = dt
⇒ xn-1dx = (1/n).dt
By partial Fraction:-
⇒ 1 = A(t - 1) + B(t)
Put t = 0:-
⇒ 1 = A(-1)
⇒ A = -1
Put t = 1:-
⇒ 1 = B
⇒ B = 1 then
We know that:-
Put the value of t:-
We know that:-
log m - log n = log (m/n)
Solun:- Let f(x) =
Integrate f(x):-
Let sin x = t
Differentiate w.r.t. to t:-
⇒ cos x.dx = dt
By partial Fraction:-
⇒ 1 = A(2 - t) + B(1 - t)
Put t = 1:-
⇒ 1 = A(1)
⇒ A = 1
Put t = 2:-
⇒ 1 = B(-1)
⇒ B = -1 then
We know that:-
Put the value of t:-
We know that:-
log m - log n = log (m/n)
Solun:- Let f(x) =
Integrate f(x):-
Put x2 = t
By quotient rule:-
By partial Fraction:-
⇒ 2t + 5 = A(t + 4) + B(t + 3)
Put t = - 4:-
⇒ - 3 = B(- 1)
⇒ B = 3
Put t = - 3:-
⇒ - 1 = A(1)
⇒ A = -1 then
Put t = x2
We know that:-
Solun:- Let f(x) =
Integrate f(x):-
Let x2 = t
Differentiate w.r.t. to t:-
2x.dx = dt
By partial Fraction:-
⇒ 1 = A(t + 3) + B(t + 1)
Put t = - 1:-
⇒ 1 = A(2)
⇒ A = 1/2
Put t = - 3:-
⇒ 1 = B(-2)
⇒ B = -1/2 then
We know that:-
Put the value of t:-
We know that:-
log m - log n = log (m/n)
Solun:- Let f(x) =
Integrate f(x):-
Let x4 = t
Differentiate w.r.t. to t:-
⇒ 4x3.dx = dt
⇒ x3.dx = (1/4).dt
By partial Fraction:-
⇒ 1 = A(t - 1) + B(t)
Put t = 1:-
⇒ 1 = B(1)
⇒ B = 1
Put t = 0:-
⇒ 1 = A(-1)
⇒ A = -1 then
We know that:-
Put the value of t:-
We know that:-
log m - log n = log (m/n)
Solun:- Let f(x) =
Integrate f(x):-
Let ex = t
Differentiate w.r.t. to t:-
⇒ ex.dx = dt
⇒ dx = (1/ex).dt
⇒ dx = (1/t).dt
By partial Fraction:-
⇒ 1 = A(t - 1) + B(t)
Put t = 1:-
⇒ 1 = B(1)
⇒ B = 1
Put t = 0:-
⇒ 1 = A(-1)
⇒ A = -1 then
We know that:-
Put the value of t:-
Choose the correct answer in each of the Exercises 22 and 23.
Solun:- Let f(x) =
Integrate f(x):-
By partial Fraction:-
⇒ x = A(x - 2) + B(x - 1)
Put x = 1:-
⇒ 1 = A(-1)
⇒ A = - 1
Put x = 2:-
⇒ 2 = B(1)
⇒ B = 2 then
We know that:-
We know that:- n.log m = log mn
log m - log n = log (m/n)
The correct answer is B.
Solun:- Let f(x) =
Integrate f(x):-
By partial Fraction:-
⇒ 1 = A(x2 + 1) + (Bx+C)(x)
Put x = 0:-
⇒ 1 = A(1)
⇒ A = 1
Put x = 1:-
⇒ 1 = 1(2) + (B+C)(1)
⇒ B + C = - 1
Put x = - 1:-
⇒ 1 = 1(2) - (- B + C)(1)
⇒ - B + C = 1
⇒ C = 0 and B = - 1 then
Let x2 + 1 = t
Differentiate w.r.t. to t:-
⇒ 2x.dx = dt
⇒ x.dx = (1/2).dt
We know that:-
The correct answer is A.
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