Math Challenge #1

[Jackc]

1+2+3+4...+1000 is 500500
find formular for this question.
(N=final number (at the top one, is 1000)

I know the answer

 

[Octavian X]

Yeah, I know.... I.... I..... just want everyone else to have a chance! Yeah, everybody should have a chance.... Yeah....

 

[Perfection]

f(x)=.5x^2+.5x of course!

 

[Octavian X]

I knew that!

 

[col]

or average term x no of turns = (1+1000)/2 * 1000

Standard AP. Sniff.

 

[Dell19]

Since there are no rules on who gets to ask the next question, heres another one:

Given that: y = e to the power of x squared - x

find the value of dy/dx if x = 1

 

[ainwood]

Is that (e^x)² - x or e^(x²) - x or (e^(x²-x))??

 

[Dell19]

The third one

 

[Vlad Antlerkov]

[deleted]

 

[Dominix]

Originally posted by ainwood
(e^(x²-x))??

dy/dx = (2x-1)(e^(x²-x))

@1 = 1

Trig proof (don't you love them?)

Prove that (sin[x])^4 = (0.25(cos²[x]-1))²

btw, how did you get that squared to work ainwood? (I just copied it off his reply)

 

[onejayhawk]

Dominix, did your post come out correct? The way you wrote it, it reduces easily to (sin x)^4=-(sin x)^4/16 which is always false except x=0.

Here is a nut cracker. Most people are aware of a the caltrop. Its a physical item resembling a jack (the childs toy). thrown on the ground, one pint is always straight up.

Assume an ideal caltrop, ie segments from the center of a regular 4 sided pyramid to the 4 verticies. If each segment is measure x, what is the height of the entire construct.

Hint. Work with the pyramid. Slice it.

 

[Jackc]

The most convincing answer was by 'col'.
yep, that's right.
you don't have to use 'sin's and things.

 

[Dominix]

Originally posted by onejayhawk
Dominix, did your post come out correct? The way you wrote it, it reduces easily to (sin x)^4=-(sin x)^4/16 which is always false except x=0.

Here is a nut cracker. Most people are aware of a the caltrop. Its a physical item resembling a jack (the childs toy). thrown on the ground, one pint is always straight up.

Assume an ideal caltrop, ie segments from the center of a regular 4 sided pyramid to the 4 verticies. If each segment is measure x, what is the height of the entire construct.

Hint. Work with the pyramid. Slice it.

Yeh ur right, I wrote the wrong thing lol... Get back later when I figure out what it was supposed to be lol...

 

[Perfection]

1.5X!!!

What's the Derivitive of the function f(x)=Sin x

 

[scorch]

-cosx



hmmmm if i had a formula sheet i could do it

 

[Hitro]

Originally posted by Perfection
1.5X!!!

What's the Derivitive of the function f(x)=Sin x

Is that supposed to be the sinus hyperbolicus?

If that's the case it's Cos x (meaning cosinus hyperbolicus).
If you mean the sinus itself it is cos x. (not -cos x).

 

[ainwood]

Originally posted by Dominix
btw, how did you get that squared to work ainwood? (I just copied it off his reply)

Hold down ALT, and type 0178.

Alt+0177 is ±
Alt+0178 is ²
Alt+0179 is ³

 

[Perfection]

Originally posted by Hitro

Is that supposed to be the sinus hyperbolicus?

If that's the case it's Cos x (meaning cosinus hyperbolicus).
If you mean the sinus itself it is cos x. (not -cos x).

Sorry I just started calc 1, maybe in a while I can give you a better answer.

 

[col]

If all else fails, listen to what the teacher says.

Sometimes we're right.

 

[col]

What's the next number in this series?

3,3,5,4,4,...