Find A for Partial Fractions 1/(x+5)^2 (x-1)

In summary, to find the value of A in the given equation, you will need to use the method of comparing coefficients on both sides of the equation. This involves setting up and solving a system of equations using the given values of B and C.
  • #1
pillar
35
0
1/(x+5)^2 (x-1)
B=(-1/6) C=(1/36)

I can't find the value of A, what method do you use to find it?
 
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  • #2
pillar said:
1/(x+5)^2 (x-1)
B=(-1/6) C=(1/36)

I can't find the value of A, what method do you use to find it?

b]1/(x+5)^2 (x-1)[/b] = A/(x+5) + B/(x + 5)^2 + C/(x - 1)
Put x = 0.
 
  • #3
pillar said:
1/(x+5)^2 (x-1)
B=(-1/6) C=(1/36)

I can't find the value of A, what method do you use to find it?

[tex]\frac{1}{(x+5)^{2}(x-1)}[/tex] will disintegrate into [tex]\frac{Ax+B}{(x+5)^{2}} + \frac{C}{x-1}[/tex]

Compare coefficients on both sides to get

A = -1/36
B = -11/36
C = 1/36
 
  • #4
Ok thank, now what about this problem?

[tex]\frac{(x)^3}{(x+4)^{2}}[/tex] will disintegrate into [tex]x+4[/tex]=[tex]\frac{Ax+B}{(x+4)^{2}}[/tex]

I'm not sure where to go from there, to get the values of A & B.
 
  • #5
pillar said:
Ok thank, now what about this problem?

[tex]\frac{(x)^3}{(x+4)^{2}}[/tex] will disintegrate into [tex]x+4[/tex]=[tex]\frac{Ax+B}{(x+4)^{2}}[/tex]

I'm not sure where to go from there, to get the values of A & B.

[tex]\frac{(x)^3}{(x+4)^{2}}[/tex] will disintegrate into

[tex]\frac{(x+4-4)^3}{(x+4)^2}[/tex]

which you can expand using the [tex](a+b)^3[\tex\ standard formula and then its the same as the last one. Compare coefficients of powers of x on both sides to get A,B,C and so on.
 

FAQ: Find A for Partial Fractions 1/(x+5)^2 (x-1)

What are partial fractions?

Partial fractions is a method for breaking down a rational function into simpler fractions. It involves finding the individual components, or partial fractions, that make up the original function.

Why do we use partial fractions?

Partial fractions can be used to simplify complex rational functions, making them easier to integrate, differentiate, or manipulate in other ways. It is also useful in solving systems of linear equations.

How do we find the partial fractions for a given function?

The first step is to factor the denominator of the rational function. Then, for each distinct linear factor, we create a partial fraction with a numerator of the form Ax + B, where A and B are constants. For each distinct quadratic factor, we create a partial fraction with a numerator of the form Ax + B, where A and B are constants, and the denominator is the quadratic factor.

What is the purpose of finding "A" in the partial fraction 1/(x+5)^2 (x-1)?

The constant "A" in this partial fraction represents the coefficient of the linear term in the original function. It is necessary to find this value in order to fully break down the original function into its partial fractions.

Can we find partial fractions for any rational function?

Yes, partial fractions can be used for any rational function, as long as the denominator can be factored into distinct linear and quadratic factors.

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