Posted: 3/14/2010 10:21:26 PM EDT
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Hey, I am studying for the GMAT, and I am currently doing Domain/Range of function stuff....and I really forget how to do this stuff. I know the domain can't be things like a 0 in the denominator, a negative in a square root, and a negative absolute value (i think...), but I think I might be missing something.
Also, I totally forgot how to find the range. An example from each section of my review questions: f(x) = (4x-1)/(x-3) f(x) = |x-6| -3 f(x) = 2 - sqroot(x-5) f(x) = x^2 + 8x +11 Any help would be greatly appreciated. The book I have (from EZ solutions) doesn't do that good of a job covering this. |
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Absolute value is always +.
The absolute value of -2 ( I -2 I )is 2. Look at this |
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Quoted:
Hey, I am studying for the GMAT, and I am currently doing Domain/Range of function stuff....and I really forget how to do this stuff. I know the domain can't be things like a 0 in the denominator, a negative in a square root, and a negative absolute value (i think...), but I think I might be missing something. Also, I totally forgot how to find the range. An example from each section of my review questions: f(x) = (4x-1)/(x-3) f(x) = |x-6| -3 f(x) = 2 - sqroot(x-5) f(x) = x^2 + 8x +11 Any help would be greatly appreciated. The book I have (from EZ solutions) doesn't do that good of a job covering this. So wait... Are you just trying to find just the range? Or do you need help solving them too? I can probably help you some. |
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Quoted:
Hey, I am studying for the GMAT, and I am currently doing Domain/Range of function stuff....and I really forget how to do this stuff. I know the domain can't be things like a 0 in the denominator, a negative in a square root, and a negative absolute value (i think...), but I think I might be missing something. Also, I totally forgot how to find the range. An example from each section of my review questions: f(x) = (4x-1)/(x-3) f(x) = |x-6| -3 f(x) = 2 - sqroot(x-5) f(x) = x^2 + 8x +11 Any help would be greatly appreciated. The book I have (from EZ solutions) doesn't do that good of a job covering this. So wait... Are you just trying to find just the range? Or do you need help solving them too? I can probably help you some. I think I have domains down...but not sure where to begin on the ranges |
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Hey, I am studying for the GMAT, and I am currently doing Domain/Range of function stuff....and I really forget how to do this stuff. I know the domain can't be things like a 0 in the denominator, a negative in a square root, and a negative absolute value (i think...), but I think I might be missing something. Also, I totally forgot how to find the range. An example from each section of my review questions: f(x) = (4x-1)/(x-3) f(x) = |x-6| -3 f(x) = 2 - sqroot(x-5) f(x) = x^2 + 8x +11 Any help would be greatly appreciated. The book I have (from EZ solutions) doesn't do that good of a job covering this. So wait... Are you just trying to find just the range? Or do you need help solving them too? I can probably help you some. I think I have domains down...but not sure where to begin on the ranges Well, we know that the range is all the points of the y-axis contained on the graph. So for example, if you graph out your example number two, you would move it 6 units left and 3 down... and the graph would open upwards... So D: (infinity, infinity) and R: [-3,infinity). Man... I'm raking my memory right now and can't remember too much, it's been a couple years since I took Calc. and I'm quickly realizing that I should probably start brushing up on it too cause I'll be taking my GMAT soon enough as well. These are a lot easier to do if you have the actual graph to look at, but I don't believe that is the case... Sorry, I thought I could help but I don't think it's going to turn out that way tonight. |
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Couldn't you just solve for x and y and chart points working that way?
So for f(x)= (4x-1)/(x-3) Let x=4 and solve for f(4), which would be 15.. so then you would have your first point of (4,15).[/span] And then just keep charting enough until you're able to make a graph? 
Edit: I can't even make simple calculations right now... I'm going to bed. |
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Domain is anything left to right on the x axis. This can be anything from - infinity to infinity.
Range is the max and the min. of the Y axis and can run from - infinity to infinity In your first example, the domain can be anything because there are no restrictions. So the answer would be {X|X = R} or (-infinity to infinity) For an absolute value, you cannot have a negative absolute value For square root you would have to set the discriminant greater than zero. and solve. The quadratic has no restrictions. Remember that f(x) is referring to Y. and whatever you plug in for the f(x) value, you would plug in for every value of x on the other side of the equation. |
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Domain is anything left to right on the x axis. This can be anything from - infinity to infinity. Range is the max and the min. of the Y axis and can run from - infinity to infinity In your first example, the domain can be anything because there are no restrictions. So the answer would be {X|X = R} or (-infinity to infinity) For an absolute value, you cannot have a negative absolute value For square root you would have to set the discriminant greater than zero. and solve. The quadratic has no restrictions. Remember that f(x) is referring to Y. and whatever you plug in for the f(x) value, you would plug in for every value of x on the other side of the equation. Thanks, man. |