Two questions about functions

[otterpop]

I came across this problem when working on an online class and have no idea what circle the symbol stands for. Is it multiplication?



I also couldn't even figure out what this question was asking. He wants the river on three sides? Does the river curve? Can anyone reword it so that it makes sense, or is it confusing to you too? - EDIT: AH! Maybe I get it now. The word "enclose" might have been throwing me off. So, there is one, straight river. He wants two fence sides running perpendicular, and one parallel, making a three sided fence with a river as the fourth side of the rectangular field - no fence needed. Yes? Also, I still think the question is really confusing.



This is my first post on this forum. Thanks in advance for the help.

 

[stapel]

I came across this problem when working on an online class and have no idea what circle the symbol stands for. Is it multiplication?

\(\displaystyle f(x)\, =\, \sqrt{x\, +\, 1}\, \mbox{ and }\, g(x)\, =\, 3x\, -\, 4\)

\(\displaystyle \mbox{Find }\, h(x)\, =\, \left(f\, \circ\, g\right)(x)\)

Neither your textbook nor your instructor covered "function composition" before you were tested on it?!? Wow. That's... wow. :shock:

To learn what "composition" is and how to do it, please try online lessons, such as the lessons listed here.

I also couldn't even figure out what this question was asking. He wants the river on three sides? Does the river curve? Can anyone reword it so that it makes sense, or is it confusing to you too? - EDIT: AH! Maybe I get it now....

A farmer wants to enclose a rectangular field along a river on three sides. If 4,400 feet of fencing is to be used, what dimensions will maximize the enclosed area?

Draw a picture of the situation:

---------------------
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
---------------------
   |              |
 w |              |
   *--------------*
         L

The width of the paddock is "w"; the length is "L". The river is the fourth side, so the perimeter is w + L + w = 4400 and the area is A = wL.

 

[otterpop]

Neither your textbook nor your instructor covered "function composition" before you were tested on it?!? Wow. That's... wow. :shock:

To learn what "composition" is and how to do it, please try online lessons, such as the lessons listed here.

It's an online, learn at my own pace kind of thing, so no professor, otherwise I would have asked them.

And I am usually quite capable at finding this information on my own, but you can't exactly look up a symbol in the index of your book. I couldn't find it, going back to review the chapter. I think the book wrote it down in words, rather than using the circle symbol.

Thanks for your help.

 

[Dale10101]

Sugesstion

It's an online, learn at my own pace kind of thing, so no professor, otherwise I would have asked them.

And I am usually quite capable at finding this information on my own, but you can't exactly look up a symbol in the index of your book. I couldn't find it, going back to review the chapter. I think the book wrote it down in words, rather than using the circle symbol.

Thanks for your help.

Self study, very cool. If you can afford to invest about 20 bucks a great reference book for learning algebra manipulations is "The Humongous Book of Algebra Manipulation" The author Michael Kelly specifically avowed to write a text in which no steps in a solution are skipped, he gives a lot of good tips too. The book is a compendium of solved problems.

Also, online is great but getting a couple of beginner/intermediate algebra books from a second hand book store provides a great reference source. Unlike most online sources the topics are developed from basic concepts. Of course there is always the library ... they might have Kelly's book to peruse before buying. Just trying to help, good luck, and yes, this site is a great source ... love it.