Monday, February 25, 2013

Partial Fractions Method


In algebra the partial fraction method decomposition or partial fraction method expansion is used to reduce the degree of either the numerator or the denominator of a rational function. The outcome of a full partial fraction method expansion expresses that function as a sum of fractions. In symbols, one can use partial fraction method expansion to change a rational function in the form. (Source: wikipedia)

Having problem with Partial Derivative Notation keep reading my upcoming posts, i will try to help you.

General Notation of Partial Fractions method with Example:

General Steps to be followed in partial fractions:

Step 1: First we can divide the terms into partial fractions

Step 2: This is known as A and B

Step 3: We can plug any value for A

Step 4: We can get the value for A

Step 5: We can plug A value on the one of the equation

Step 6: Then we have to get the value of B

Step 7: These A and B are the solutions of this partial fractions.

General Notation and Example Problems on the Partial Fractions Method:

Problem 1:

If we wants to decompose (m)/(m+n) , then one can follow these steps:

Write as

(m)/(m+n) = A +(B)/(m+n)

Here A, B and n are known as constants.

Multiply both sides by m+n

m = A(m+n) +B

m = A.m + A.n +B

Here A and B must simultaneously solve:

m = A.m

0 = A.n + B

Because the coefficients of both m and 1 have to agree, giving rise to the two equations.

Therefore here A = -1 and B = -a

Finally, the decomposed form is:

(m)/(m+n) = 1+(-n)/(m+n)

These are the general notation of partial fractions method.

Between, if you have problem on these topics Even Number Chart, please browse expert math related websites for more help on cbse sample papers for class 9 for sa2.

Problem 2:

Simplify   5              into partial fractions.using partial fraction method
(x + 1)(x + 2)

Solution:

((5)/((x+1)(x+2)))

it can be written as

(A)/(x+1) + (B)/(x+2)

Taking L.C.M and simplifyning this we get,

5 = A(x+2) + B(x+1)

5 = Ax +2A + Bx +B

Plug x=-1 we get

5 = -A + 2A - B + B

here B get cancelled

Then

5 = A

Therefore A = 5

Again consider

5=Ax +2A + Bx +B

Plug x=-2 we get

5=-2A +2A +B(-2) +B

Here -2A and 2A get cancelled

5=-B

Therefore B=-5

Therefore the solution of these partial Equation is A=5and B=-5

No comments:

Post a Comment