oh the joy of maths homework.

yah, learned that in grade 10 preAP in Canada. Not so bad; like some of the others have been saying, the calculator does all the work. Doing it by hand isn't that bad either

 

Am I the only guy who learned quadratic equations in 8th (age 13-14) grade? o.o

 

Nope. I took intro to algebra in 7th grade, which is where I first learned about quadratic equations.

 

i learnt it when i was 13.

 

Nice comment from somebody who doesn't know how a calculator works internally. The picture you show, shows absolutely no proof on the method I mentioned used for factorization. A simple answer could be:

- input of form: a*x^2 + b*x + c
- compute roots using step 1 of the picture in post 1.
- echo "(x - root1)(x - root2)"

This is how most online calculators would do it. It shows the same results you show, but uses a completely different method than I mentioned for factorization. Who's the idiot now?

An alternative is to use GCF and determine the second term, but this is slow (for computers). It's just like factoring integers, which has its application in cryptology for being overly complicated for large numbers.

A TI-89 uses a fairly complicated system to factor polynomals and do all other maths. Yet it is only a machine, and it's not even perfect. It fails for certain polynomals and is slow for others. Try factoring this:

Code:

(x^6)+2*(x^3)-(x^2)+1 = (x^3+x+1)(x^3-x+1) = should fail

And this:

Code:

(x^40)+(x^30)+(x^20)+(x^10)+1 = ((x^20)+(x^15)+(x^10)+(x^5)+1)((x^20)-(x^15)-(x^10)-(x^5)+1) = slow, 15 minutes

 

Nowhere did you state in your post that you were referring to the algorithms performed within the calculator.

Fact is, computers and calculators can be "taught tricks", though the algorithm may not match the process of human intuition. Of course I know that the calculator doesn't factor equations via intuition, which you didn't specify in your post.

Also, the TI-89 actually happens to be quite inferior in regards of capability and processing power. That's why software packages such as Mathematica and MATLAB exist. TI-89s are not suitable or reliable to handle heavy-duty computations such as high-degree polynomials. Also, your 6th-order polynomial that you found just underscores the flaw within the TI-89 itself.

That screenshot that I posted was proof that computers being able to factor has already been done. It doesn't matter if it was done in the same way as humans can do it. And now, computers are able to take on Laplace and Fourier Transforms which humans normally do by hand, using tables.

 

I absolutely hate the fact that I'm in a lower maths class (don't ask) so my teacher thinks we can't handle quadratic equations -_-"

 

I did.

At least we agree on that.

So what you're saying with that last line is that your screenshot post is actually bogus. My whole point is that you can't teach a computer insight or intuition, like I posted.

 

Huh? Words "maths" and "joy" in one sentence? History and languages are more fun, I'm out of here!

 

Spoken like a real alpha...

 

ugh i hate math i remeber learnig somthing like this

when in life will we need to know how to graph a quadratic equation???

 

Hypr, the problem given in the first post isn't grade 8 math, grade 8 maths involve graphs but you don't do this. I don't remember what grade you learn this though.

Math is mandatory in school because it's all logical problem solving. It helps develop the brain so it can think logically. That's why logic puzzles are in math.

You will probably never need to know how to find x in a quadratic equation or find how many people there are in a percentile in comparison with the ratio/normale with respect to "l'ecarte type" (Don't know the english word). But you will need to understand how these things work and how you have to work them down to the point where you find the answer.

 

no im helping an 8th grader in math tis is way tocomplex for them