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The function f(x) varies inversely with x and f(x)=2 when x=16.

What is f(x) when x=4?
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8

User Phillippa
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2 Answers

5 votes

Answer:

8

Explanation:

User Craigmoliver
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5.6k points
6 votes
The correct answer is: [D]: "8" .
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When x = 4, f(x) = 8 .

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Given the problem:
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The function; "f(x)" ; varies inversely with "x" ; and "f(x) = 2 when x = 16 " .

What is f(x) when x = 2?
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Explanation:
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Note that: f(x) = y .

If y varies inversely with x; then y = k/x ; with "k" being the "constant" in this equation.

You can find the constant by substituting the values given: x = 16, f(x) = y = 2 ;

So, f(x) = y = 2 = k/16 ;

→ 2 = k / 16 ;

Solve for the constant; "k" ;

Multiply EACH SIDE of the equation by "16"

→ 16* (2) = (k / 16) * 16 ;

→ 32 = k ;

↔ k = 32 ;

As such, we can write the equation:

y = k/ x ;

as:

→ y = 32/ x ;

Since we are given: "x = 4" ; Plug in that value; and solve for "y" ;

y = 32/4 = 8 .

y = 8 .

y = f(x) ;

So; f(x) = 8 ; which is: Answer choice: [D]: "8" .
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User Ishank
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5.5k points