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a : If 1/((x-2)(x^(2)+1))=A/(x-2)+(Bx+C)...

a : If `1/((x-2)(x^(2)+1))=A/(x-2)+(Bx+C)/(x^(2)+1) " then "A=1/5, B=-1/5, C=-2/5`.
R : `1/((x-a)(x^(2)+b))=1/(a^(2)+b)[1/(x-a)-(x+a)/(x^(2)+b)]`

A

Both A & R are true and R is correct explanation of A

B

Both A & R are true and R is not correct explanation of A

C

A is true but R is false

D

A is false but R is true

Text Solution

AI Generated Solution

The correct Answer is:
To solve the equation \[ \frac{1}{(x-2)(x^2+1)} = \frac{A}{x-2} + \frac{Bx+C}{x^2+1} \] we will find the values of \(A\), \(B\), and \(C\) using the method of partial fractions. ### Step 1: Combine the right-hand side First, we need to express the right-hand side with a common denominator: \[ \frac{A}{x-2} + \frac{Bx+C}{x^2+1} = \frac{A(x^2+1) + (Bx+C)(x-2)}{(x-2)(x^2+1)} \] ### Step 2: Expand the numerator Now, we will expand the numerator: \[ A(x^2 + 1) + (Bx + C)(x - 2) = Ax^2 + A + Bx^2 - 2Bx + Cx - 2C \] Combining like terms gives us: \[ (A + B)x^2 + (-2B + C)x + (A - 2C) \] ### Step 3: Set the numerators equal Now, we set the numerators equal to each other since the denominators are the same: \[ 1 = (A + B)x^2 + (-2B + C)x + (A - 2C) \] ### Step 4: Compare coefficients Since the left-hand side has no \(x^2\) or \(x\) terms, we can compare coefficients: 1. Coefficient of \(x^2\): \(A + B = 0\) (Equation 1) 2. Coefficient of \(x\): \(-2B + C = 0\) (Equation 2) 3. Constant term: \(A - 2C = 1\) (Equation 3) ### Step 5: Solve the equations From Equation 1, we can express \(B\) in terms of \(A\): \[ B = -A \] Substituting \(B = -A\) into Equation 2: \[ -2(-A) + C = 0 \implies 2A + C = 0 \implies C = -2A \] Now substituting \(C = -2A\) into Equation 3: \[ A - 2(-2A) = 1 \implies A + 4A = 1 \implies 5A = 1 \implies A = \frac{1}{5} \] Now substituting \(A\) back to find \(B\) and \(C\): \[ B = -A = -\frac{1}{5} \] \[ C = -2A = -2 \cdot \frac{1}{5} = -\frac{2}{5} \] ### Final Values Thus, we have: \[ A = \frac{1}{5}, \quad B = -\frac{1}{5}, \quad C = -\frac{2}{5} \] ### Conclusion The values of \(A\), \(B\), and \(C\) are indeed: \[ A = \frac{1}{5}, \quad B = -\frac{1}{5}, \quad C = -\frac{2}{5} \]
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