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Assume the function f(x) is defined as follows: f(x) =
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22 Jul 2019, 02:51
22 Jul 2019, 02:51
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60% (00:52) correct
39% (01:08) wrong based on 138 sessions
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Assume the function f(x) is defined as follows: \(f(x) = (x – 4)^2 + \sqrt{x+3} + \frac{5}{x+2}\). For which of the following values of x is f(x) defined?
Indicate all such values.
A. –5
B. –4
C. –3
D. –2
E. –1
Indicate all such values.
A. –5
B. –4
C. –3
D. –2
E. –1
Re: Assume the function f(x) is defined as follows: f(x) =
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24 Jul 2019, 10:24
24 Jul 2019, 10:24
1
here we need to consider two constraints.
We can't have square root of negative numbers. So, x+3 >=0 or, x>= -3
We can't have denominator 0. So x+2 not equal i.e. x not equal -2
From first constraint, we get values -3, -2, -1. But from the second constraint, we have to exclude -2. Thus, -3 and -1 are our answers.
We can't have square root of negative numbers. So, x+3 >=0 or, x>= -3
We can't have denominator 0. So x+2 not equal i.e. x not equal -2
From first constraint, we get values -3, -2, -1. But from the second constraint, we have to exclude -2. Thus, -3 and -1 are our answers.
Re: Assume the function f(x) is defined as follows: f(x) =
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30 May 2020, 11:56
30 May 2020, 11:56
2
What does it mean to be undefined?
There are a lot of situations that are undefined, but two of the most common in GRE-level math are 1) taking the square root of a negative number and 2) dividing by zero.
For each of the items being added up, you only have to look at two: sqrt(x+3) and 5/(x+2)
For the first, x has to be greater than or equal to -3 in order to not be a negative number under the square root sign. Eliminate A and B.
For the second, x cannot be equal to -2 so that you're not dividing by zero. Eliminate D.
For the values of X for answers C and E, you've got a defined equation. Those are the answers!
There are a lot of situations that are undefined, but two of the most common in GRE-level math are 1) taking the square root of a negative number and 2) dividing by zero.
For each of the items being added up, you only have to look at two: sqrt(x+3) and 5/(x+2)
For the first, x has to be greater than or equal to -3 in order to not be a negative number under the square root sign. Eliminate A and B.
For the second, x cannot be equal to -2 so that you're not dividing by zero. Eliminate D.
For the values of X for answers C and E, you've got a defined equation. Those are the answers!
