• Mar 8th 2009, 01:10 PM
tigerpaw
If xRy = x-y = 7t

Is the equation:
reflexive
symmetric
transitive
• Mar 8th 2009, 01:34 PM
Plato
Quote:

Originally Posted by tigerpaw
If xRy = x-y = 7t

Is the equation:
reflexive
symmetric
transitive

You need to show some work.
At least explain what you don't understand.
BTW: R appears to be a relation. Is that correct?
What is t?
• Mar 8th 2009, 02:11 PM
tigerpaw
thank you for your help. I read xRy as x is related to y which normally indicates an ordered pair.

I am confused from that point, the only remaining question then reads then x – y = 7t and if this equation is reflexive and/or symmetric and/or transitive

thanks
• Mar 8th 2009, 02:31 PM
Plato
Well first I find it hard to think a Praxis question is so poorly written.
This is not an equation but rather set of ordered pairs.
Each pair $\displaystyle (x,y)$ is in the collection is there if and only if $\displaystyle x – y = 7t$ for some $\displaystyle t$.
Reflexive: Is $\displaystyle 7 \cdot 0 = x - x$ true for every $\displaystyle x$?
Symmetric: If $\displaystyle x - y = 7t$ does it follow that $\displaystyle y - x = 7( - t)$?
Transitive: $\displaystyle x - y = 7t\;\& \,y - z = 7s\, \Rightarrow \,x - z = 7(t + s)$.

May I ask, what level of the Praxis are you studying for? Is it the subject matter area test?
• Mar 8th 2009, 03:38 PM
tigerpaw
Absolutely, it is the Praxis II High school math content knowledge.

A great number of the questions are extremely vague with little information.

I have a few more questions that I have seen if you are interested. thanks
• Mar 8th 2009, 04:49 PM
Plato
Quote:

Originally Posted by tigerpaw
Absolutely, it is the Praxis II High school math content knowledge. A great number of the questions are extremely vague with little information.
I have a few more questions that I have seen if you are interested.

I have both written for and edited for these test.
Do you realize that the area exam of the Praxis assumes an equivalence of an undergraduate major in the subject matter?
Many U.S. states have adopted that standard for secondary certification.
In mathematics that becomes a great problem!
Here in the states it is relatively easy to move among several subject disciplines.
BUT, that is not our experience with mathematics.
Unfortunately we have found that a complete undergraduate course in mathematics was a prerequisite for passing the Praxis subject area test in mathematics.

You need to know that finding.
• Mar 8th 2009, 06:01 PM
tigerpaw
thank you, that I have discovered and I have sought the additional courses. I teach in a very low income rural county school with an enrollment close to 450 students. I agree with your statement regarding the the undergraduate experience and accompanying technical knowledge needed to pass the Praxis. I teach basic algebra and geometry to students who fall thru the cracks and fight to keep them in school. As imagined, I have struggled with the advanced portions of the exam. Also, many of the views seen in the discrete portion of the subject matter have been difficult. regardless, thank you for your help.