Resolve resolve X³/(x-a){x-b}[x-c] into partial fractions please
Answers
Answer:
Resolve x^3/((x-a)(x-b)(x-c)) into partial fractions.
Updated On: 22-2-2020
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Step-by-step explanation:
Given :-
X^3/(x-a){x-b}[x-c)
To find :-
Resolve r X^3/(x-a){x-b}[x-c] into partial fractions?
Solution :-
Given that
x^3/(x-a){x-b}[x-c)
Let x^3/(x-a){x-b}[x-c) = A/(x-a)+ B/(x-b) + C/(x-c)
x^3/(x-a){x-b}[x-c) = >
[A(x-b)(x-c)+ B(x-a)(x-c) + C(x-a)(x-b)]/(x-a){x-b}[x-c)
On cancelling (x-a)(x-b)(x-c) both sides then
x^3 = A(x-b)(x-c)+ B(x-a)(x-c) + C(x-a)(x-b)-----(1)
Put x = a in (1) then
a^3 = A(a-b)(a-c)+ B(a-a)(a-c) + C(a-a)(a-b)
=>a^3 = A(a-b)(a-c)+B(0)+C(0)
=> a^3 = A(a-b)(a-c)+0+0
=> a^3 = A(a-b)(a-c)
=>A = a^3/(a-b)(a-c)--------(2)
Put x = b in (1) then
=> b^3 = A(b-b)(b-c)+ B(b-a)(b-c) + C(b-a)(b-b)
=> b^3 = A(0)+B(b-a)(b-c)+C(0)
=> b^3 = 0+B(b-a)(b-c)+0
=> b^3 = B(b-a)(b-c)
=> B = b^3/(b-a)(b-c) ---------(3)
Put x = c in (1) then
c^3 = A(c-b)(c-c)+ B(c-a)(c-c) + C(c-a)(c-b)
=> c^3 = A(0)+B(0)+C(c-a)(c-b)
=> c^3 = 0+0+C(c-a)(c-b)
=> c^3 = C(c-a)(c-b)
=> C = c^3/(c-a)(c-b)---------(4)
Now
On Substituting the values of A ,B and C in the given equation then it becomes
x^3/(x-a){x-b}[x-c) = A/(x-a)+ B/(x-b) + C/(x-c)
=> [a^3/(a-b)(a-c)]/(x-a)+[ b^3/(b-a)(b-c)]/(x-b)
+[c^3/(c-a)(c-b)/(x-c)
Answer:-
x^3/(x-a){x-b}[x-c) = [a^3/(a-b)(a-c)]/(x-a)+[b^3/(b-a)(b-c)]/(x-b) +[c^3/(c-a)(c-b)/(x-c)