The plot above shows the graph of function f(x). For what integer valu

Question

https://gmatclub.com/forum/download/file.php?id=49124 The plot above shows the graph of function f(x). For what integer value of x in the interval shown does f(x) = x + 1? A. -2 B. -1 C. 0 D. 1 E. 2 #GREpracticequestion The plot above shows the.jpg

Shishou · Answer

we are looking for an x value that gives us a y or f(x) value that is 1 more than that x value. Looking at the graph x=-1 corresponds to an f(x) value of 0 which is 1 more than x which is -1. Answer is B

taukir · Answer

explain it please.

yashikaaggarwal · Answer

Solve by options.
Let's put X = -2
F(X) = X+1 
=> -2+1 => -1 = Y
SO THE COORDINATE IS (-2,-1),

SIMILARLY, with other values of X given in options.
X = -1 , Y = 0 => {-1,0}
X = 0 , Y = 1 => {0,1}
X = 1 , Y = 2 => {1,2}
X = 2 , Y = 3 => {2,3}

Among all plotted points in diagram, only (-1,0) is satisfying the points on diagram. Hence B is the Answer.
 taukir  hopefully it explains everything

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Kinshook · Answer

Given: The plot above shows the graph of function f(x). 
Asked: For what integer value of x in the interval shown does f(x) = x + 1?

f(-1) = -1 + 1 = 0

IMO B

rickc · Answer

Hi taukir,

Try thinking of it this way. When you have a function you will have an input and an output. For f(x) the input is x and the output will be y.

For example, using the above graph: When the x coordinate is 1 what is the y coordinate? Look at the graph to determine. The y cordinate will be 5.

This is the same as saying f(1) = 5

Here are some more from the same function f(x) When x=3, y will be 3.
When x=5, y will be 4.

Moving on to this question now. It is asking "what value of x will give the output of x + 1?" Or another way to frame the question is, "When the x coordinate equals a number when will the y coordinate number be one greater than x?"

Let's try sub in all the possible answers so we can enforce the concept.

f(x) = x + 1?

A) -2 f(-2) = -2+1 = -1, looking at the graph when the x coordinate is -2, y is 1, this is wrong

B) -1 f(-1) = -1+1 = 0, looking at the graph when the x coordinate is -1, y is 0, this is correct, the y value is the same as x+1.

C) 0 f(0) = 0+1 = 1, but looking at the graph, y=2. This isn't correct

D)1 f(1) = 1+1 = 2, but looking at the graph, y=5. This is incorrect.

E)2 f(2) = 2+1 = 3, but looking at the graph y=4. This is incorrect.

The only solution that y equals 1 greater than the x input is B.

Hope this helps anyone looking for some clarity.

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bumpbot · Answer

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The plot above shows the graph of function f(x). For what integer valu

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The plot above shows the graph of function f(x). For what integer valu

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