If kx3 + 4x2 + 3x – 4 and x3 – 4x + k leave the same remainder when divided by (x – 3), then the value of k is:
Show answer & explanation
Correct answer: D
Explanation
The correct answer is Option 4 i.e. -1.
| Understanding/Application |
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p(x) = kx3 + 4x2 + 3x - 4 f(x) = x3 - 4x + k g(x) = x - 3 Using Factor theorem - x - 3 = 0 x = 3 Remainder = p(3) |
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As both leave same remainder - k33 + 4(3)2 + 3(3) - 4 = 33 - 4(3) + k 27k + 36 + 5 = 27 - 12 + k 26k + 41 = 15 26k = - 26 k = -26/26 k = -1 |