Please solve it as fast as possible with explanation.
Answers
Answer:
k = -4
h = 1
Step-by-step explanation:
f(x) = x³ + kx² + hx + 6
according to factor theorem, for f(x) to be a factor of both (x+1) and (x-2), f(-1) and f(2) = 0
=> f(-1) = (-1)³ + k(-1)² +h(-1) + 6 = 0
=> -1 + k - h + 6 = 0
=> k + 5 - h = 0
and f(2) = (2)³ + k(2)² + h(2) + 6 = 0
=> 8 + 4k + 2h + 6 = 0
=> 4k + 14 + 2h = 0
=> 2k + 7 + h = 0
adding both equations, 3k + 12 = 0
=> k = -4
=> h = -4 + 5 = 1
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➤ Solution :
f (x) = x³ + kx² + hx + 6
according to the factor theorem, for f (x) to be a factor of both ( x + 1 ) and ( x - 2 ) , f (-1) and f (2) = 0
➜ f (-1) = (-1)³ + k (-1) ² + h (-1) + 6 = 0
➜ -1 + k - h + 6 = 0
➜ k + 5 - h = 0
and f (2) = (2)³ + k (2)² + h (2) + 6 = 0
➜ 8 + 4k + 2h + 6 = 0
➜ 4k + 14 + 2h = 0
➜ 2k + 7 + h = 0
adding both equations , 3k + 12 = 0