Find the value of ‘k’ if the polynomials 2x³ + kx² + 3x - 5 and x³ + x...
Introduction:To find the value of 'k' such that the polynomials 2x³ + kx² + 3x - 5 and x³ + x² - 4x - k leave the same remainder when divided by (x-1), we will use the Remainder Theorem.
Remainder Theorem:The Remainder Theorem states that if a polynomial f(x) is divided by (x-a), the remainder is equal to f(a).
Step 1: Divide the polynomials by (x-1):We will divide the polynomials 2x³ + kx² + 3x - 5 and x³ + x² - 4x - k by (x-1) using long division.
2x² + (k+2)x + (k+3)
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x - 1 | 2x³ + kx² + 3x - 5
2x³ - 2x²
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(k+2)x² + 3x
(k+2)x² - (k+2)x
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4x - 5
4x - 4
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-1
The remainder is -1.
x² - 3x + (k-1)
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x - 1 | x³ + x² - 4x - k
x³ - x²
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2x² - 4x
2x² - 2x
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-2x - k
-2x + 2
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-k - 2
The remainder is -k - 2.
Step 2: Equate the remainders:Since the two polynomials leave the same remainder when divided by (x-1), we equate the remainders obtained.
-1 = -k - 2
Step 3: Solve for 'k':To solve for 'k', we will isolate the variable on one side of the equation.
-1 + 2 = -k
1 = -k
k = -1
Conclusion:The value of 'k' that makes the polynomials 2x³ + kx² + 3x - 5 and x³ + x² - 4x - k leave the same remainder when divided by (x-1) is k = -1.