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Re: For what value of x between -5 and 1 inclusive, the value of 6x^2-x^4
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14 Mar 2019, 12:55
kiran120680 wrote:
For what value of x between -5 and 1 inclusive, the value of 6x^2–x^4-4 is greatest?
A. -5 B. -√5 C. -2 D. -√3 E. 1
if we use -5,it will give a very large negative value, so cancel it. the larger the value,the more negative it will keep getting. just check for -\sqrt{3} and 1.
Re: For what value of x between -5 and 1 inclusive, the value of 6x^2-x^4
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15 Mar 2019, 10:32
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kiran120680 wrote:
lucajava wrote:
I differentiated:
\(12x - 4x^3 = 0\)
\(x^3 - 3x = 0\)
\(x(x^2 - 3) = 0\)
\(x = {0, +\sqrt{3}, -\sqrt{3}}\)
Since there is only \(-\sqrt{3}\) among the options, pick it up.
Can you please explain elaborately
In math, the first derivative is used to find max. and min. values of a function. Starting from this point, i differentiated to find the \(x\) where the function takes the greatest value. Hope it's clear.
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50% (01:49) correct 
