Back to college - math help?

k9handler · 07-05-2008, 11:48 AM

I need some basic math help, topic is sets.

I understand the sections leading up to this (Union, Intersection, Complimant, etc).

Not sure how to write these out.

3. Take out a coin for the following problems:
a. Suppose you are going to flip a coin once. What is the set of possible outcomes for this?
b. Suppose you are going to flip a coin twice. What is the set of possible outcomes for this?
c. If flip a coin twice, what are the chances that you will get one head and one tail (i.e. one in three, one in four, etc.)? Use your answer to the question 3b to get your answer.

mcuozzo · mcuozzo's Garage

Well, lets see

3a. If you flip a coin once the sets are

heads
tails

3b. if you flip a coin twice the sets are:

heads/heads
heads/tails
tails/heads
tails/tails

3c. So when flipping a coin twice you have a 2 in 4 chance of getting one head/one tail combo. or a 50 percent chance.

I'm sure others will chime in and tell me I'm wrong!!!

k9handler · 07-05-2008, 12:10 PM

That was my initial thought, so I just need to write it in set form I guess. Thank you for your help.

RWebb · RWebb's Garage

- what you really need is some book that makes it easy to think about sets...

wish I knew of one.

is there a Dummies Guide?

Are you goinig to MSU? U of M?

k9handler · 07-05-2008, 12:55 PM

No I am going through TUI University, online college.

I have looked over some of the help sites, yet they still leave some confusion.

Pretty sure I have this first module completed correctly.

mcuozzo · mcuozzo's Garage

Huh, maybe I don't know what you mean by "set form".

The set of answers to 3a = {Heads, tails}
The set of answers to 3b ={heads/heads, heads/tails, tails/heads, tails/tails}

You're not asked to do anything else but list the members of the sets right? No intersections, unions, bisections, etc.

Similarly 3c just asks the percent not to write it out as subsets, correct?

Or maybe this is just new math that is way beyond me!!!

k9handler · 07-05-2008, 02:22 PM

No your correct, just the way I worded it. The brackets is all I was talking about. Thanks again for your help.

k9handler · 07-10-2008, 04:11 PM

Answer the following questions and if required to do calculations please show your work:

Thanks, got all A's for the week 1 assignments.

More help if you can.

1. Which of the following are functions? Explain your reasoning for a, b, and c.

a. f(x) = 2 if x>1 otherwise f(x) = -1

b. f(x) = 5 if x>0 or f(x) = -5 if x<0 or f(x) = 5 or -5 if x = 0

c. f(x) = x/10

k9handler · 07-10-2008, 04:17 PM

My thought is
a. is not a function due to multiple variables.
b. is a function
c. is a function

I read that functions produce one value...can anyone break this down for a dummie like me?

k9handler · 07-10-2008, 06:17 PM

ok this is really messing with me...f(x) and tables, graphs, functions....blah blah blah.

I have looked over several sites talking about this and yet none of them make sense to where I can write and equation on my own.

help.

Pazuzu · 07-10-2008, 06:37 PM

A function means that the independent variable has only one dependent value associated with it.

In other words, for F(x)=4x:
x is the independent variable
F(x) is the dependent variable.

So, for a given x, there is one and only one value of F(x).

Does this help?

k9handler · 07-10-2008, 06:56 PM

It helps but for some reason I just can't seem to get a solid grasp of the concept and answer the questions in my assignment. I even have my daughters graphing calculator...can't figure that damn thing out either.

onewhippedpuppy · 07-11-2008, 04:52 AM

I would think that c is the only function, because a and b don't have x in them. a and b have function of x equal to a constant, which doesn't seem like a function. I guess it depends on how you define a function?

What kind of math class is this? I just finished an aerospace engineering degree, and took math through differential equations. You just confused me.

Jim Richards · 07-11-2008, 05:18 AM

Quote:

Originally Posted by k9handler

ok this is really messing with me...f(x) and tables, graphs, functions....blah blah blah.

I have looked over several sites talking about this and yet none of them make sense to where I can write and equation on my own.

help.

Hey Smitty, Pazuzu gave you a great answer. It might also help to draw pictures of these problems (I'm more of a visualization guy - must watch cartoons!

). You know, "x" on the horizontal axis and "F(x)" on the vertical axis. Then, just draw lines, points, whatever and see how the equations look. If more than one value of F(X) at any point, x, then, it's not a function.

Jim Richards · 07-11-2008, 05:19 AM

"b" isn't a function because it has two possible values of F(x) at x=0.

Pazuzu · 07-11-2008, 05:33 AM

Quote:

Originally Posted by Jim Richards

"b" isn't a function because it has two possible values of F(x) at x=0.

Correct. Both (a) and (c) are functions, because for any value of x (the independent variable) there is one and one one value of F(x), therefore, they fit the basic rule of being a function.

(b) isn't a function, because there is a case where there are 2 values of F(x) for a single value of x...therefore, it breaks the rule.

Pazuzu · 07-11-2008, 05:35 AM

Quote:

Originally Posted by onewhippedpuppy

What kind of math class is this? I just finished an aerospace engineering degree, and took math through differential equations. You just confused me.

I had to go back and look up the definition of a function

You tend to loose those building blocks when you hit your 4th or 5th year of n-dimensional calculus.

So, k9handler, don't think I'm smart or anything, because I did not have that information off the top of my head

k9handler · 07-11-2008, 10:46 AM

ok fellas thanks for the help...I do get it a little better now that I see your explanations and answers. I was up pretty late and ended up just closing it all up and taking another look at it today with fresh eyes and a clear mind.

k9handler · 07-11-2008, 10:57 AM

Onto another area in the section, linear or non-linear?

example:

For each of the relationships below, explain whether you think it is best described by a linear function or a non-linear function. Explain your reasoning thoroughly

a. How fast it takes you to get to work as a function of how fast you drive

b. Probability of getting into a car accident as a function of how fast you drive

c. Your height as a function of age (from age 0 to 100)

I say (a) is best solved by a non-linear, too many variables beyond just speed and time.
(b) no idea
(c)...hmmm linear as the line or curve can be solved with a basic function using a x/y axis? SWAG on my part

masraum · 07-11-2008, 11:11 AM

Quote:

Originally Posted by k9handler

Onto another area in the section, linear or non-linear?

example:

For each of the relationships below, explain whether you think it is best described by a linear function or a non-linear function. Explain your reasoning thoroughly

a. How fast it takes you to get to work as a function of how fast you drive

b. Probability of getting into a car accident as a function of how fast you drive

c. Your height as a function of age (from age 0 to 100)

I say (a) is best solved by a non-linear, too many variables beyond just speed and time.
(b) no idea
(c)...hmmm linear as the line or curve can be solved with a basic function using a x/y axis? SWAG on my part

Wikipedia can be your friend.
http://en.wikipedia.org/wiki/Linear_function

I believe that linear means "straight line" or first order, ie y=2x+5, 2y+3x=10, etc.... You shouldn't see any variables with an exponent of anything but 1, so no y=x^2.

My guess on A is that they are talking about the straight line basic approach, ie 30 miles at 15 mph --> 2 hrs, 30 miles at 30 mph --> 1 hr, etc..., which is linear.

I would say that B is non linear

C is also non linear