[quote]LIFTICVSMAXIMVS wrote:
This is why the Indians and Chinese own every technical contracting job across the US.[/quote]
could be because math is more of a fundamental in their culture. but hey, it could because im asking for math help on T-Nation too.
[quote]Backlash79 wrote:
B rocK wrote:
good luck with the math. in the real world they let us use calculators and other people. aka asians.
hilarious.[/quote]
roflmao @ asian comment
7
A cat was climbing up a tree, and a dog on the ground was running directly toward the tree. When the cat’s owner first looked out her back window, the cat was 3 m above the ground, and climbing at a rate of 2 m/sec, while the dog was 4 m from the tree and running at a speed of 7 m/sec.
How fast was the distance between the cat and the dog decreasing at that time?
I fucking hate these questions. Operationally, they are easy, but I find designing the formulas very hard. Unfortunately, my final exam will probably be mostly stuff like this. Anyone have any tips?
[quote]Thomas Gabriel wrote:
A cat was climbing up a tree, and a dog on the ground was running directly toward the tree. When the cat’s owner first looked out her back window, the cat was 3 m above the ground, and climbing at a rate of 2 m/sec, while the dog was 4 m from the tree and running at a speed of 7 m/sec.
How fast was the distance between the cat and the dog decreasing at that time?
I fucking hate these questions. Operationally, they are easy, but I find designing the formulas very hard. Unfortunately, my final exam will probably be mostly stuff like this. Anyone have any tips? [/quote]
cheat. lol.
idk man, ive been studying a few hours a day solely on math for this final coming up. and no to complain but i also have a 5 page paper for my Film class due in a few days which i havent started. fun, fun, fun.
y = m*t+b
y m = m m/sec * t sec + b m
y = 2 m/sec * t sec + 4 m
dy/dt = 2 m/sec
x m = m m/sec * t sec + b m
x = 7 m/sec * t sec + 7 m
dx/dt = 7 m/sec
(dy/dt)/(dx/dt) = 2/7 = 2/7 m/sec
…dy/dt / dx/dt = dy/dt*dt/dx = dy/dx
…Notice the initial conditions i.e. starting positions had no effect on the rate.
…They will usually try to fuck you w/ the answer: is it increasing by -2/7 m/sec or decreasing by 2/7 m/sec
…These really aren’t that bad if I did it right
…Drawing the picture helps more than anything working out +/-
…Units helps a lot too, especially when talking about velocities/accelerations.
…and I ignored the acceleration due to gravity
[quote]theuofh wrote:
y = m*t+b
y m = m m/sec * t sec + b m
y = 2 m/sec * t sec + 4 m
dy/dt = 2 m/sec
x m = m m/sec * t sec + b m
x = 7 m/sec * t sec + 7 m
dx/dt = 7 m/sec
(dy/dt)/(dx/dt) = 2/7 = 2/7 m/sec
…dy/dt / dx/dt = dy/dt*dt/dx = dy/dx
…Notice the initial conditions i.e. starting positions had no effect on the rate.
…They will usually try to fuck you w/ the answer: is it increasing by -2/7 m/sec or decreasing by 2/7 m/sec
…These really aren’t that bad if I did it right. [/quote]
fuck
you
oh and what if they were in a space station with a gravational change of -10 psi (thats how they measure it right?)
Just had a college algebra final myself. Suprisingly, I ended up really liking the class, though I haven’t studied algebra in about 8 years or so. Anyways, if I can’t factor a quadratic equation quickly by sight, I do like others have suggested. Break out the quadratic formula
[quote]Sloth wrote:
Just had a college algebra final myself. Suprisingly, I ended up really liking the class, though I haven’t studied algebra in about 8 years or so. Anyways, if I can’t factor a quadratic equation quickly by sight, I do like others have suggested. Break out the quadratic formula[/quote]
i havent learned it. theres actually a few things on my final we havent gone over in class.
for example
1/k+4 - 5/k-10
3/k-10 + 2/k+3
at least he gave us like an instruction manual for how to do the problems along with the study guide.
its just hard to get something from a piece of paper, its better having someone be able to explain it.
[quote]LiveFromThe781 wrote:
red04 wrote:
You could also just know that 7 is a factor of 112/280/175… but that would be too easy
yeah, cause its so obvious.[/quote]
Hey Live, there’s actually a way to always find a common factor between a group of numbers. You do what’s called prime factorization.
So a prime number is a number (like 2, 3, 5, 7, 11, 13, and NOT like 4 = 2 * 2 or 6 = 2 * 3) that doesn’t have any factors other than 1 and itself. Factoring a number into powers of primes goes like this:
Example: 112. Well, 2 definitely goes into 112, because the number ends in 2. So 112 = 2*56. Well, 2 also is a factor of 56, so 56 = 2 * 28. Thus, 112 = 2 * 2 * 28. But 28 = 7 * 4, so that means that 112 = 2 * 2 * 2 * 7 * 4, but this can also be written as 112 = 2^5 * 7.
Example: 280. Since 280 ends in 0, that means that 10 is a factor of 280, 280 = 28 * 10. But 28 = 7 * 4, and 10 = 2 * 5, so 280 = 7 * 4 * 2 * 5 = 7 * 2^3 * 5.
We can do the same thing to find that 175 = 7 * 25 = 7 * 5^2. So, 7 is a factor of all three numbers, because it is in their prime factorization!
So, 112 x^2 + 280 x + 175 = 7 (32 x^2 + 40 x + 25), and that is a lot easier to factor.
Key tips:
Do it a step at a time. You’ll get better with practice, but try first dividing out by small primes if you don’t immediately see a bigger one that works. For example, try 2, 3, and 5 if all else fails.
There are tricks to tell if a number goes into another number evenly.
Give these a try. But honestly, if you can practice the quadratic formula, that is often even better!
This thread sucks.
2+2=4, and so on from there
[quote]PonceDeLeon wrote:
Linear algebra, differential equations, discrete mathematics, geometry and statistics will be the most useful math classes you’ll ever take.
Physics made no sense until I took diff eq’s. Discrete math is awesome for pattern recognition, stats’s utility is obvious…[/quote]
I hated discrete math with a passion… every single lecture and assignment was hell. But afterwards, it seemed to make everything else easier in comparison.
(1/k)+4-(4/k)-10 *k
(3/k)+4-(4/k)-10 *k
…If they are over the same number multiply by it
1+4k-4-10k
3+4k-4-10k
…looks much easier
-6k-3
-6k-1
…you’re on your own from there. I would probably just circle that and call it the answer.
[quote]LiveFromThe781 wrote:
the length of a table top is 4 m greater than the width. the area is 77m^2. Find the dimensions
its a pain in the ass trying to copy what i have on my paper to the screen especially when theres no math keys.
but right now heres where im stuck
(w^2)(4w) - 154 = 0
i cant find a number that adds to equal 4 but multiplys to get -154. is there some kind of easier method to find this out other than jamming numbers on a calculator for 45 minutes?[/quote]
Yup.
Get a TI-89. Go to algebra tab, select 2:factor( , and enter the polynomial.
Factoring is good practice though. Teaches you to pull shit apart and look at all of its parts.
while most math has no practical application in the real world, i agree its good because it does challenge you to think in a different kind of way and improving that type of thinking will help you out in logical situations.
…it just sucks having finals lol
Factoring sucks. FOIL sucks. Quadratics suck. Math is lame. School sucks. I can’t wait for it to be over. I got finals to study for, l8ta.
[quote]elano wrote:
Factoring sucks. FOIL sucks. Quadratics suck. Math is lame. School sucks. I can’t wait for it to be over. I got finals to study for, l8ta.[/quote]
Perhaps you should just drop out and prepare for a mediocre life serving other people. You don’t need math skills to shine people’s shoes, for example.
[quote]Sloth wrote:
Just had a college algebra final myself. Suprisingly, I ended up really liking the class, though I haven’t studied algebra in about 8 years or so. Anyways, if I can’t factor a quadratic equation quickly by sight, I do like others have suggested. Break out the quadratic formula[/quote]
Being able to solve a quadratic equation with a formula isn’t nearly as important as knowing when it can or cannot be applied and knowing the consequences of certain constraints – such as imaginary results.
These days any calculator will figure that out.
Knowing why is way more important for problem solving than knowing how because chances are someone else has already done the work and figured out how to solve it. Being an efficient problems solver requires knowing where to look for the answer sometimes.
[quote]LIFTICVSMAXIMVS wrote:
Sloth wrote:
Just had a college algebra final myself. Suprisingly, I ended up really liking the class, though I haven’t studied algebra in about 8 years or so. Anyways, if I can’t factor a quadratic equation quickly by sight, I do like others have suggested. Break out the quadratic formula
Being able to solve a quadratic equation with a formula isn’t nearly as important as knowing when it can or cannot be applied and knowing the consequences of certain constraints – such as imaginary results.
These days any calculator will figure that out.
Knowing why is way more important for problem solving than knowing how because chances are someone else has already done the work and figured out how to solve it. Being an efficient problems solver requires knowing where to look for the answer sometimes.[/quote]
I can’t speak for anyone else in my class, but I kind of enjoyed finding solutions the old fashioned way. In fact, I probably learned less about the use of my calculator than anything else this semester. I really only used the thing for logs and exponential functions.