#1

just started learning derivatives in calculus and our teacher does these equations that take up full pages. i look at the kids next to me paper and his equations dont even take up a quarter of a page. is there an easier way to do these things? im no where near being smart for math but any tips to make it easier would help

#2

Violence.

It is the answer to EVERY problem.

It is the answer to EVERY problem.

#3

derivatives = teh win

you just have to get a feeling for it, then you don't even have the drag them out

wait until you get up to integrals

you just have to get a feeling for it, then you don't even have the drag them out

wait until you get up to integrals

#4

Violence.

It is the answer to EVERY problem.

Only if the teacher is a woman, though.

#5

is there a shorter way to do these things?

#6

just started learning derivatives in calculus and our teacher does these equations that take up full pages. i look at the kids next to me paper and his equations dont even take up a quarter of a page. is there an easier way to do these things? im no where near being smart for math but any tips to make it easier would help

Example problem?

#7

maybe he just skipped a few stages

like said above, just do a lot of them, and you'll get faster

like said above, just do a lot of them, and you'll get faster

#8

Just started? So like you learned how to differentiate 3x²?

It gets a lot more complicated.

It gets a lot more complicated.

#9

it depends, if you do it one step at a time, then of course its going to take a page. The trick is mixing steps together

#10

I think derivatives are fun. Much better than integrals anyway. And theres no easy way. You'll just get used to it. Just need to practice them. And if you are planning to stick to the science field, physics mostly, you will have to know how to do them. They come up everywhere.

#11

well my teacher is from india and that doesnt help much either

#12

derivates is not as much about beeing smart or good in math as to figure out the trick, how to think in order to solve it. I was pretty good ad derivates and integrals in school, but I suck at math otherwise.

#13

no im in business marketing but u need to take 2 semesters of math. and this is my first semester

#14

well my teacher is from india and that doesnt help much either

Yes, we Indians tend to be annoyingly good at math :p

#15

and those dam asians. but im talking in terms of accent. every time she says (X+H). the way she says H makes me want to listen to fall out boy

#16

and those dam asians. but im talking in terms of accent. every time she says (X+H). the way she says H makes me want to listen to fall out boy

Just admit you want to listen to fall out boy. Give in to your inner emo-ness, and then maths won't understand you, either.

Sorry.

#17

@Swat Man - Hehe, cant argue with you there. Has to be difficult. But look past that and you will find that derivatives aren't that hard. Just takes practice.

#18

LOL. but seriously is there a shortcut

#19

yes there are shortcuts that you will probably be taught after you learn how to do it the long way.... such as

x^2 the derivatve is 2x... you get this by taking the exponent and copying it to the coefficent, then subtract one from the exponent... more examples

x^3 is 3x^2

x^(1/2) is (1/2)x^(-1/2) ... this is actually for the square root cuz square root of x is x^(1/2)

x^2 the derivatve is 2x... you get this by taking the exponent and copying it to the coefficent, then subtract one from the exponent... more examples

x^3 is 3x^2

x^(1/2) is (1/2)x^(-1/2) ... this is actually for the square root cuz square root of x is x^(1/2)

#20

You'll get taught the short way.

truth be told, I 've totally forgotten what the long way is xD

We did differentiation again for the first time since we broke up for christmas last year. I could've cried cos I didn't remember it.

Now we're onto radians D:

Stupid radians.

truth be told, I 've totally forgotten what the long way is xD

We did differentiation again for the first time since we broke up for christmas last year. I could've cried cos I didn't remember it.

Now we're onto radians D:

Stupid radians.

#21

Just wait until logarithms....damn you C2 mixed exercise on logarithms, damn you to hell.

#22

LOL. but seriously is there a shortcut

Yeah, there is...are you using the definition of a derivative? Like the limit as h approaches zero blah blah? Because I mean all you have to do for basic polynomials is multiply the exponent of the term by the variable, and then subtract one from the exponent.

For example, the derivative of 10x^5 is 50x^4. You multiply the 5 in the exponent by the 10 (50) and then subtract one from the 5.

If you've been doing it that way and it still takes that long then you should probably quit calculus.

#23

A shortcut to what exactly? You need to know all the trig idents, you need to know all the common derivatives and integrals and you need to know how to apply them. It's just practice.

If derivatives make Jesus cry, then triple integrals must crucify him.

If derivatives make Jesus cry, then triple integrals must crucify him.

#24

Calculus is easy.

****ing sequences and series are bastards.

I hate first principles though

****ing sequences and series are bastards.

I hate first principles though

#25

Thats exactly how people can do rubik's cubes in under 20 seconds. Exactly.it depends, if you do it one step at a time, then of course its going to take a page. The trick is mixing steps together

#26

and those dam asians. but im talking in terms of accent. every time she says (X+H). the way she says H makes me want to listen to fall out boy

you're still doing the stuff with limits?

lim (h->0) ((f(x+h)-f(x))/h)

yeah, thats the long way, more in actual graphical definition of the derivative. You should learn the quicker rules for differentiation in a week or so

*Last edited by seljer at Jan 31, 2008,*

#27

You said she was talking about (x+h)? I assume you know the equation for first principles:

This is easy. I take it you do understand the principles of functions, correct? F(2) would be the quation where you replace all values of x with a 2. F(5) you would replace the values of x with a 5, and so on... So for F(x+h), you would replace all values of x with x+h.

Take the equation 3x^2 + 2x + 5:

It gets simpler, once you use it more.

ax^b differentiates to abx^(b-1)

Then theres all the different rules... product rules, quotient rules, bracket rules... You need them going over in depth?

edit: crap... I completely forgot about sin, cos, tan, sin-1, cos-1, tan-1, sec, cosec, cot, ln, e, etc...

```
F'(x) = limit | F(x+h) - F(x) |
h -> 0 | ------------- |
| h |
```

This is easy. I take it you do understand the principles of functions, correct? F(2) would be the quation where you replace all values of x with a 2. F(5) you would replace the values of x with a 5, and so on... So for F(x+h), you would replace all values of x with x+h.

Take the equation 3x^2 + 2x + 5:

```
F'(x) = limit | F(x+h) - F(x) |
h -> 0 | ------------- |
| h |
Therefore:
F'(x) = limit | (3(x+h)^2 + 2(x+h) + 5) - (3x^2 + 2x + 5) |
h -> 0 | ----------------------------------------- |
| h |
F'(x) = limit | 3x^2 + 3h^2 + 6xh + 2x + 2h + 5 - (3x^2 + 2x + 5) |
h -> 0 | ------------------------------------------------- |
| h |
F'(x) = limit | 3h^2 + 6xh + 2h |
h -> 0 | --------------- |
| h |
F'(x) = limit | 3h + 6x + 2 |
h => 0
Therefore, as h tends to 0,
F'(x) = 6x + 2
```

It gets simpler, once you use it more.

ax^b differentiates to abx^(b-1)

Then theres all the different rules... product rules, quotient rules, bracket rules... You need them going over in depth?

edit: crap... I completely forgot about sin, cos, tan, sin-1, cos-1, tan-1, sec, cosec, cot, ln, e, etc...

*Last edited by umop-3p!sdn at Jan 31, 2008,*

#28

You'll get taught the short way.

truth be told, I 've totally forgotten what the long way is xD

We did differentiation again for the first time since we broke up for christmas last year. I could've cried cos I didn't remember it.

Now we're onto radians D:

Stupid radians.

Did anyone do the Maths C2 module this year? Half of the whole ****in' paper was in radians

I could've cried.

#29

You haven;t got to show loads of working or anything. It should only be 2 lines.

y=3x^2 + 4x

dy/dx = 6x +4

And that's all you have to write

C2 rocks my ****, it's great stuff man and you'll need to know your radians; they're a major part of C3 AND C4.

y=3x^2 + 4x

dy/dx = 6x +4

And that's all you have to write

Did anyone do the Maths C2 module this year? Half of the whole ****in' paper was in radians

I could've cried.

C2 rocks my ****, it's great stuff man and you'll need to know your radians; they're a major part of C3 AND C4.

#30

You'll get taught the short way.

truth be told, I 've totally forgotten what the long way is xD

Yeah, once they teach you the short way TS, it'll all be really easy. I don't remember how to do the long way anymore either...

#31

Did anyone do the Maths C2 module this year? Half of the whole ****in' paper was in radians

I could've cried.

its not bad until you **** a math test since your calculator was accidently on grads

#32

You shouldnt just forget everything after you've been taught it. For example, on Further Pure 1 this year, I had a question on first principles...

#33

its not bad until you **** a math test since your calculator was accidently on grads

You can usually tell can't you lol.

I.E. Sin40 = 0.717

Surely you'd think "Does it?" and then realise your calc is still in Radian mode.

#34

You haven;t got to show loads of working or anything. It should only be 2 lines.

y=3x^2 + 4x

dy/dx = 6x +4

And that's all you have to write

C2 rocks my ****, it's great stuff man and you'll need to know your radians; they're a major part of C3 AND C4.

It could've been ok, except our teacher sort of ... forgot to teach us what they are until the week before. Luckily I do physics and already knew

#35

It could've been ok, except our teacher sort of ... forgot to teach us what they are until the week before. Luckily I do physics and already knew

But seriously, get a new teacher. We did that in a day at the beginning of the year. It's practically the basics.

#36

I've spent one evening drunkenly solving differentials and integrals for like half of all the other electrical engineering students freshmen

(well alright...just a dozen of them)

(well alright...just a dozen of them)