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If x ≥ 0, then must be equal to 0.07x8 0.07x4 0.7x14 0.7x8 0
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27 Oct 2018, 16:47
27 Oct 2018, 16:47
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73% (00:34) correct
26% (00:33) wrong based on 78 sessions
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If x ≥ 0, \(\sqrt{0.49x^{16}}\)then must be equal to
A. \(0.07x^8\)
B. \(0.07x^4\)
C. \(0.7x^{14}\)
D. \(0.7x^8\)
E. \(0.7x$4\)
A. \(0.07x^8\)
B. \(0.07x^4\)
C. \(0.7x^{14}\)
D. \(0.7x^8\)
E. \(0.7x$4\)
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Re: If x ≥ 0, then must be equal to 0.07x8 0.07x4 0.7x14 0.7x8 0
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28 Oct 2018, 07:32
28 Oct 2018, 07:32
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sandy wrote:
If x ≥ 0, \(\sqrt{0.49x^{16}}\)then must be equal to
A. \(0.07x^8\)
B. \(0.07x^4\)
C. \(0.7x^{14}\)
D. \(0.7x^8\)
E. \(0.7x$4\)
A. \(0.07x^8\)
B. \(0.07x^4\)
C. \(0.7x^{14}\)
D. \(0.7x^8\)
E. \(0.7x$4\)
Useful property: \(\sqrt{xy} = (\sqrt{x})(\sqrt{y})\)
So, \(\sqrt{0.49x^{16}} = (\sqrt{0.49})(\sqrt{x^{16}})\)
\(= (0.7)(x^8)\)
Answer: D
ASIDE: A common mistake is to conclude that \(\sqrt{x^{16}} = x^4\)
However, notice that \((x^4)(x^4) = x^8\), not \(x^{16}\)
Conversely, \((x^8)(x^8) = x^{16}\)
Re: If x ≥ 0, then must be equal to 0.07x8 0.07x4 0.7x14 0.7x8 0
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14 Jun 2020, 10:23
14 Jun 2020, 10:23
Since √x = x^1/2, can I say that √x^16 = x^(16/2) = x^8 ?
