- #1

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## Homework Statement

Which of the following statements are true?

A)

If f(x)=e

^{x}, then f(x)⋅f(-x)=1

B)

If g(x)=1/x, then g (1/x)=x

C)

If h(x)=√(x+2), then h(2)=±2

## Homework Equations

## The Attempt at a Solution

Only B

- Thread starter Jaco Viljoen
- Start date

- #1

- 160

- 9

Which of the following statements are true?

A)

If f(x)=e

B)

If g(x)=1/x, then g (1/x)=x

C)

If h(x)=√(x+2), then h(2)=±2

Only B

- #2

Mark44

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I agree, but why do you think that A and C are not true?## Homework Statement

Which of the following statements are true?

A)

If f(x)=e^{x}, then f(x)⋅f(-x)=1

B)

If g(x)=1/x, then g (1/x)=x

C)

If h(x)=√(x+2), then h(2)=±2

## Homework Equations

## The Attempt at a Solution

Only B

- #3

- 160

- 9

A) doesn't seem to make sense to me... although x is still unknown.

C)The answer would be 2 not ±2.

C)The answer would be 2 not ±2.

- #4

Mark44

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But even without having a specific value for x, can't you evaluate f(x) - f(-x), to see whether it comes out to 1? Otherwise your answer is nothing more than a guess.A) doesn't seem to make sense to me... although x is still unknown.

Yes.Jaco Viljoen said:C)The answer would be 2 not ±2.

- #5

- 160

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If f(x)=e^{x}, then f(x)⋅f(-x)=1 Not true:

-e^{x}

-e

- #6

Ray Vickson

Science Advisor

Homework Helper

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In (A), it looks to me as though you are writing (i): ##f(x) \times f(-x)##, while Mark44 seems to see (ii): ##f(x) - f(-x)##. Which do you mean: (i) or (ii)?## Homework Statement

Which of the following statements are true?

A)

If f(x)=e^{x}, then f(x)⋅f(-x)=1

B)

If g(x)=1/x, then g (1/x)=x

C)

If h(x)=√(x+2), then h(2)=±2

## Homework Equations

## The Attempt at a Solution

Only B

- #7

Mark44

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