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andyhaus1057
Oct 10, 2008, 07:21 PM
Hello,
Can you please help with these? I would greatly appeciate it.

1) True or False - The following relation is a function: {(1, 2), (3, 4), (5, 5)}
False?

2) True or False - The following relation is a function: {(3, 4), (3, 5, (4, 4), (4, 5)}
True?

3) Evaluate f(x) = 3x + 7 at 5(4)
I know it has to be either 45, 14, 19, or 28 and my guess is 14


4) f(x) = 4x^2 - 1 / c^2 at f(-2)
I know it has to be either 4/15, 15/4, 1/2 or 11/20 my guess is 15/4


5) f(x) = x^3 - x
I know it has to be either an odd function, an even function, or neither and my guess is that its an odd function.


6) f(x) = 2x^2 + x^4 + 1 Is either an odd function, an even function, or neither. My guess is that its an even function.

7) Write an equation in slope-interception form for the line passing through (3, 5) and (8, 15)

I think this one is a..

a) y = 2x - 1
b) y = 3x + 8
c) y = -2x - 1
d) y = x + 15


8) Write an equation in slope-intercept form for the line passing through points (-2, 0) and (0, 2)

I think this one is b..

a) y = -2x + 1
b) y = x + 4
c) y = x + 2
d) y = -x


9) Find the slope for the line passing through points (2, 1) and (3, 4)
Has to be either 7, 6, 1 or 3 and I think its 6

10) Find the slope for the line passing through points (6, -4) and (4, 2)
Has to be either 1, 0, 10 or -1 and I think its 10

Unknown008
Oct 11, 2008, 03:14 AM
A function is one where there is only one possible answer for a given point. The first one is True.

The second is false because there are the coordinates (3, 4) and (3, 5). Let's say you were given and equation, saying that it is a function. And you get two answers for 3, then it is not a function. This is more obvious for (3, 5) and (4, 5) where there are two points with the y coordinate as 5.

I'll be here later, need to go.

andyhaus1057
Oct 11, 2008, 06:20 PM
OK,
Thank you for your help. Can you please help me with the others?

andyhaus1057
Oct 11, 2008, 06:36 PM
Here is what I have done so far...

1) True - The following relation is a function: {(1, 2), (3, 4), (5, 5)}

2) False - The following relation is a function: {(3, 4), (3, 5, (4, 4), (4, 5)}

6) f(x) = 2x^2 + x^4 + 1 even function

4) f(x) = 4x^2 - 1 / c^2 at f(-2) answer is 15/4 4^2 - 1
f(x) = -------
x^2


Write an equation in slope-interception form for the line passing
>through (3, 5) and (8, 15)

a) y = 2x - 1


I know that this one I can check by plugging each ordered pair
into your chosen equation and seeing if it is true in each case:

5 = 2(3) - 1 is true
15 = 2(6) - 1 is true


>I think this one is C.. I know it is not B
>
>a) y = -2x + 1
>b) y = x + 4
>c) y = x + 2
>d) y = -x

Unknown008
Oct 31, 2008, 02:44 AM
Ok, very sorry for the very very late reply... I did not get the mail notifications, and was very busy with my exams, which are still going on.

FYI, I am not very familiar with even or odd functions, but the answers for 1) and 2) are good.

As for 4) I don't understand well where the 'c' came from, but if it's an 'x' too, your answer is good.

Your equation is also good.

For 8), yes it is C, you could have checked the same way as you did for the previous number.

0 = -2 + 2 - true
2 = 0 + 2 - true

Ok!:)