for all you math wizzards out there, I need help!!!!!!

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Messages 21 - 40 of total 130 in this topic << First  |  < Previous  |  Show All  |  Next >  |  Last >>
jgill

Boulder climber
Colorado
Feb 21, 2014 - 11:35pm PT
Spend less time thinking about the rock and more time thinking about the math.
whitemeat

Big Wall climber
San Luis Obispo, CA
Topic Author's Reply - Feb 21, 2014 - 11:37pm PT
number 48 is B? me thinks so! send ed!!!!
JLP

Social climber
The internet
Feb 21, 2014 - 11:39pm PT
For #10, take the derivative and set it equal to zero...
Gary Carpenter

climber
SF Bay Area
Feb 21, 2014 - 11:40pm PT
4 out of 3
4 out of 3
Credit: Gary Carpenter
Cragman

Trad climber
June Lake, California....via the Damascus Road
Feb 21, 2014 - 11:51pm PT
You MUST be an aid climber....
Jim Clipper

climber
from: forests to tree farms
Feb 22, 2014 - 02:14am PT
Not counting coup, but I liked Mr. Hartouni's snappy answers and sound advice ... Wasn't there something about inflection points too?

if it is any help whitemeat, i remember a math professor saying that he always felt some frustration before solving a problem, then relief when he found the answer.

Maybe check this site as a reward for every few problems you solve too.
Clint Cummins

Trad climber
SF Bay area, CA
Feb 22, 2014 - 02:18am PT
(2x+4)(2x+5) for number 9 clint???
No, that doesn't work (you do get 4x^2 + 20, but you don't get 0*x).
But you are doing the "guessing" process of factoring right.

9. 4*x^2 + 20 = 0

This one you don't have to factor, because there is only one term with "x" in it. Factoring is for when there are both x^2 and b*x .
So for 9, just use simpler algebra to get the one x term on the left side and everything else on the right. Then it's fast to solve for x.

In general, there are just a couple of tools for quadratic equations, and you try to use the one that is fastest.

1. a*x^2 + c = 0
2. b*x + c = 0
Only one x term - just solve direct for x as above.

3. x^2 + b*x + c = 0
A. First try factoring as (x+r)(x+s), by guessing integers.
If c is negative, r and s are opposite sign, right?
If b is negative, at least one of r and s is negative.
B. If your guesses don't work, use the quadratic equation (it is slower
but always works, and it also tells you if the solution is imaginary).

4. a*x^2 + b*x + c = 0
If everything divides by a, do that and try factoring.
Otherwise use the quadratic equation.
neebee

Social climber
calif/texas
Feb 22, 2014 - 05:05am PT
hey there say, ... clint and ed, are setting out some very good advice...

me, as mom, well, i'd say this:

go back and find out WHY you can't do this...

and build up from there...
once you solve that, the trail will be a lot easier...

build upon good foundation, however:
you may be failing the test here, first,
with my advice, :O

but the next time, hopeful, you'd be 'soaring above' :)



best wishes, hang in there...
moosedrool

climber
Stair climber, lost, far away from Poland
Feb 22, 2014 - 10:34am PT
Found a solution to your math problems:

Wolfram Mathematica 9.0 Mathematica Student Edition Download
Wolfram Research will help you master your homework or even analyzing your fantasy football team, Mathematica 9 will give you an edge in both your classes and your life. ...

But seriously, this is YOUR homework. Do the work. When you go climbing you don't ask people to haul your ass, do you?

Those problems are not that difficult. You can do it!

Andrzej

rgold

Trad climber
Poughkeepsie, NY
Feb 22, 2014 - 11:16am PT
It's nice that Clint has gone into full tutoring mode. I'm not going to do that myself, for reasons that should be evident from what I've already posted.

However, it is worth mentioning, perhaps as much for others who are curious as the OP, that the first two problems require a little more knowledge than the other factoring problems, specifically the rational roots theorem, the factor theorem, and the ability to do "long division" with polynomials. Descarte's rule of signs is not essential but can be helpful in cutting down on the possibilities to be checked.

As the name of the first theorem suggests, these techniques will only work if the polynomial happens to have a rational root, which is of course the case for the given problems. But there are cubics with integer coefficients, e.g. x^3 + x^2 - 1, which have no rational roots.

The problem of finding the roots of cubic polynomials and then of higher-degree polynomials has led to an enormous amount of mathematics, including the discovery and use of complex numbers and the ground-breaking work of Evariste Galois that settled all the original questions and opened the door to research questions that are still very much alive today.
T Hocking

Trad climber
Redding, Ca
Feb 22, 2014 - 11:22am PT
Hey Mickey,
you preparing for STAR testing or High School exit exam?
Have fun huh!!!
climbski2

Mountain climber
Anchorage AK, Reno NV
Feb 22, 2014 - 11:37am PT
Some thoughts on math in general. I hated school and wasn't about to put an ounce of extra effort into it. Generally I skated by but math was a weakness, not becuase I couldn't learn. I was pretty fair at picking it up when I put effort into it. Sounds a lot like what you said earlier.

The problem with math is this. It builds up and if your foundation isn't solid you will get lost and blow out at some point.

Sadly for those who hate school this makes math rough even if they have a decent head for it. In math you HAVE to do the work. It can't really be cheated.

Oh well it seems life has chosen a different path for you. Based on your writing and math skills and clear interest in not putting your effort in school I'd say college is out for a while and climbing will be in.

Not bagging on you one bit, and I might be wrong here. You gotta follow your heart in life especially if it's burning with specific dreams. In this I suspect you are a very lucky young man, I think you've got some burning dreams and that in my short 40 years of life experience seems one of the truly valuable things to have in life.

So my advice , Be kind to all you meet, help everyway you can wherever you find yourself, Become an expert in and study what you love. Grab the opportunities that come along from time to time. If I were you I'd consider YOSAR for a couple seasons or more.
mouse from merced

Trad climber
The finger of fate, my friends, is fickle.
Feb 22, 2014 - 12:20pm PT
Add one 5.6 to another and you still can't get 5.12.

It's a two-pitch Grade I, at best.

Most laff at math. My x is a teecher of algebra in an East Bay HS.

Thank gosh she's my X!!!

http://www.jokes4us.com/miscellaneousjokes/mathjokes/algebrajokes.html
WBraun

climber
Feb 22, 2014 - 01:20pm PT
whitemeat -- "my math teacher gave me a review packet with 50 problems that I don't know how to do"

Throw them into the dumpster and go climbing.

Make the math guys do the math.

That's what they're there for.

Not everyone needs to know math beyond arithmetic.

Let all the math egomaniacs solve the math problems.

Just like brain surgeons solve those problems.

Not everyone needs to become a brain surgeon ....




ydpl8s

Trad climber
Santa Monica, California
Feb 22, 2014 - 01:55pm PT
I was a math tutor for the Boys & Girls clubs last year. It had been at least 25 yrs since I had done any of the types of problems that were like what you show here. I tried using example problems and the textbook to get caught up before a tutoring session, but it was taking too long.

Some friends told me that the intardnet now has numerous great websites where you can go online and have a video tutor walk you through each type of problem. They give enough examples so that you can actually learn (or in my case relearn) the subject, it's a great resource, take advantage of it! I was able to prepare in 30 min. for a whole slew of different students at different levels of algebra and geometry.
mouse from merced

Trad climber
The finger of fate, my friends, is fickle.
Feb 22, 2014 - 02:23pm PT
Einstein could not do the math on his own work.

He relied on others for that.

Right on, WBrain!

As usual.

One who cannot do math is not stupid.

Just bored as hell.

If you can read the sign that says Camp 4, that's about all you will need.

Pratt walked away (climbed away) from physics.

I don't mean to step on Clint and the rest who are earnest.

You guys got the best of both worlds.

One needs to settle for one's own goals, not those of the rest.

"Infinity and Point Beyond."--Buzzed Lightyears
micronut

Trad climber
Fresno/Clovis, ca
Feb 22, 2014 - 02:30pm PT
Don't listen to Werner Whitemeat!

Math (and all the other high school classes for that matter) are the "hauling" of the real world. Dirty, ugly, painful work that you gotta do if you want to be a bigwaller. Study, educate yourself while youre young, and climb until you're an old man. If you skip out and don't try hard and just go play all the time you'll be 40 years old working night shifts at Taco Bell. You've got moxy kid, we all know that. I hate math too, but get it done, don't cheat, do your own work, suffer a bit, and the summit will be within striking distance in no time.

See you this summer!

Scott
eKat

Trad climber
Less than a second shy of 49 minutes
Feb 22, 2014 - 06:02pm PT
mircronut is a wise man!

:-)
PAUL SOUZA

Trad climber
Central Valley, CA
Feb 22, 2014 - 06:21pm PT
Be good at math because there will always be someone trying to take your money.

I was horrible at math all the way through high school. Spent five years in the Navy and then went back to school. Now, my highest level of math is calculus 1. While I never use calculus now, I know bullshit when I hear it.
Guangzhou

Trad climber
Asia, Indonesia, East Java
Feb 22, 2014 - 06:48pm PT
As a Middle School math teacher, my advice is skip Number one and two and focus your time on the rest of the test. When all else is done and double checked, if you have time, go to 1 and 2.

Instead of asking for help on these equations, they are no problems in math, just equations, visit https://www.khanacademy.org/ and learn how to do these. Videos are short and excellent.

What class is this? Grade level?

Eman

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