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Chapter 36. Partial fractions & their application. Let see the example below :. If the 2 fractions are added together, the result :. is more complicated than the previous two fractions.
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Chapter 36 Partial fractions & their application By Chtan FYHS-Kulai
Let see the example below : If the 2 fractions are added together, the result : By Chtan FYHS-Kulai
is more complicated than the previous two fractions. If you want to integrate or expand the fraction, it is much simpler to express it as the sum of the two fractions. We call these fractions – the partial fractions. By Chtan FYHS-Kulai
Expression of a fractional function in partial fractions : (Rule 1) : Before a fractional function can be expressed directly in partial fractions the numerator must be of at least one degree less than the denominator. By Chtan FYHS-Kulai
e.g. 1 can be expressed in partial fractions. cannot be expressed directly in partial fractions. By Chtan FYHS-Kulai
can be simplified before it can be expressed as a sum of partial fractions. By Chtan FYHS-Kulai
(Rule 2) : Corresponding to any linear factor ax+b in the denominator of a rational fraction there is a partial fraction of the form , A is a constant. By Chtan FYHS-Kulai
e.g. 2 Express the function in partial fractions. Soln : By Chtan FYHS-Kulai
Let x=-2, -4=C(-3)(-3) Let x=1, 2=A(3)(3) Let x=-1/2, -1=B(-3/2)(3/2) By Chtan FYHS-Kulai
(Rule 3) : Corresponding to any linear factor ax+b repeated r times in the denominator, there will be r partial fractions of the form By Chtan FYHS-Kulai
e.g. 3 Express as a sum of partial fractions, Soln : By Chtan FYHS-Kulai
If x=-1, -1=-8D, D = 1/8 If x=1, -1=2C, C = -1/2 If x=0, -3=A-B+C-D -3=A-B-5/8, A-B=-19/8 1 If x=2, 5=3A+3B+3C+D 5=3A+3B-11/8, A+B=17/8 2 By Chtan FYHS-Kulai
1+2 : 2A=-2/8, A=-1/8 B=9/4 By Chtan FYHS-Kulai
(Rule 4) : Corresponding to any quadratic factor in the denominator there will be a partial fraction of the form By Chtan FYHS-Kulai
e.g. 4 Express as a sum of partial fractions, Soln : By Chtan FYHS-Kulai
Put x=1, -1=4D, D=-1/4 Put x=-1, -3=-4C, C=3/4 Put x=0, -2=-B-C+D, -2=-B-3/4-1/4, B=1 Put x=2, 6=(2A+1)(3)+5C+15D 6=3(2A+1), A=1/2 By Chtan FYHS-Kulai
Note : Repeated quadratic factors in the denominator are dealt with in a similar way to repeated linear factors. By Chtan FYHS-Kulai
Ex 16a p. 216 Mathematics 3 Q 3, 4, 5, 6, 9, 11, 12, 13, 15, 17, 20, 23, 27, 30, 32 By Chtan FYHS-Kulai
The expansion of rational algebraic fractions By Chtan FYHS-Kulai
Refer to textbook p.217 example 5 and example 6. By Chtan FYHS-Kulai
Ex 16b p. 218 Mathematics 3 Q 3, 5, 9, 11, 13, 17, 20 By Chtan FYHS-Kulai
The integration of rational algebraic fractions By Chtan FYHS-Kulai
The following types of partial fractions will arise : Beyond the scope of this book . We can integrate these types of partial fractions. By Chtan FYHS-Kulai
e.g. 5 Integrate with respect to x. Soln : By Chtan FYHS-Kulai
When x=1, 1=2C, C=1/2 When x=-1, 1=2B, B=1/2 When x=0, 1=-A, A=-1 By Chtan FYHS-Kulai
Ex 16c p. 220 Mathematics 3 All odd numbers. By Chtan FYHS-Kulai
Misc. Ex. p. 221 Mathematics 3 All odd numbers. By Chtan FYHS-Kulai
The end By Chtan FYHS-Kulai