Just factorize it!

Algebra Level 2

f ( x ) = x 4 + 4 x 2 + 2 x 3 + 3 x + 3 f(x) = x^4 + 4x^2+2x^3+3x+3

How many integer x x satisfy the condition of − 4 ≤ f ( x ) ≤ 1 5 -4 \leq f(x) \leq \dfrac{1}{5} ?


The answer is 0.

Akash Shukla by Akash Shukla , 26, India

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1 solution

Matteo Monzali
Jun 13, 2016

Just derive and find that the minimum is at x=-1/2, f(-1/2)>2, so f(x) cannot stay in the interval between -4 and 1/5

0 Helpful 0 Interesting 0 Brilliant 0 Confused

Putting the terms out of order is not helping legibility. It's a gotcha type of question, as the answer would change if one were to assume normal order.

Marta Reece - 2 years, 11 months ago

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