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Re: If f(x) = x^2 + 4 and f(2k) = 36, then which of the following is one [#permalink]
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Given that f(x) = \(x^2\) + 4 and f(2k) = 36 and we need to find one possible value of k

To find f(2k) we need to compare what is inside the bracket () * in f(2k) and f(x)

=> We need to substitute x with 2k in f(x) = \(x^2\) + 4 to get the value of f(2k)

=> f(2k) = \((2k)^2\) + 4 = \(4k^2\) + 4 = 36 (given)
=> \(4k^2\) = 36-4 = 32
=> \(k^2\) = \(\frac{32}{4}\) = 8
=> k = \(\sqrt{8}\) = \(2\sqrt{2}\)

So, Answer will be D
Hope it helps!

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Re: If f(x) = x^2 + 4 and f(2k) = 36, then which of the following is one [#permalink]
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