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Ok, I understand it's customary to post a problem. Might be a little old but it's a good 'un.

ABC is isosceles.

AB=BCAB=BC

AB=5AB= \sqrt 5

AC=2AC=2

Find a way to cut the triangle into 4 pieces so that they can be constructed to form a regular square.
Had to post this somewhere and I thought, I spend all my time in f38 so why not here:


Post 1000!!!!!!! :woo: :dance::proud::party:
Reply 1222
Ekpyrotic
Ok, I understand it's customary to post a problem. Might be a little old but it's a good 'un.

ABC is isosceles.

AB=BCAB=BC

AB=5AB= \sqrt 5

AC=2AC=2

Find a way to cut the triangle into 4 pieces so that they can be constructed to form a regular square.


Spoiler

The Muon
Had to post this somewhere and I thought, I spend all my time in f38 so why not here:


Post 1000!!!!!!! :woo: :dance::proud::party:


...:sigh:

Just joking. Congratulations, I think. :eyeball:
Ah, here's one: Factorize x^8 + x^4 + 1 into four quadratic factors each with real coefficients.
The Muon
Had to post this somewhere and I thought, I spend all my time in f38 so why not here:


Post 1000!!!!!!! :woo: :dance::proud::party:


When you get to this point you start to realize just how much of your life has been wasted on TSR
Reply 1226
Glutamic Acid
Ah, here's one: Factorize x^8 + x^4 + 1 into four quadratic factors each with real coefficients.


Nice question (a little easy though :p:)

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Reply 1227
Find the sum of the infinite series ab+a+cbd+a+2cbd2+a+3cbd3+\displaystyle \frac{a}{b} + \frac{a+c}{bd} + \frac{a+2c}{bd^2} + \frac{a+3c}{bd^3} + \cdots
Reply 1228
Kevin_B
Find the sum of the infinite series ab+a+cbd+a+2cbd2+a+3cbd3+\displaystyle \frac{a}{b} + \frac{a+c}{bd} + \frac{a+2c}{bd^2} + \frac{a+3c}{bd^3} + \cdots


A little easy again

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Reply 1229
Nice
Reply 1230
Kevin_B
Nice


Yeah, those identities are pretty much STEP II unofficial syllabus rule number 1 (from my experience)
One my teacher set us last week. It's relatively easy but fun nevertheless...

Evaluate:

0π2xsinx+cosxdx\displaystyle\int^{\frac{\pi}{2}}_0 \, \frac{x}{sinx + cosx}dx

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8 Horizontal
One my teacher set us last week. It's relatively easy but fun nevertheless...

Evaluate:

0π2xsinx+cosxdx\displaystyle\int^{\frac{\pi}{2}}_0 \, \frac{x}{sinx + cosx}dx

Spoiler



Too tired/tipsy too work it all out properly now, but:

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Reply 1233
sonofdot
Too tired/tipsy too work it all out properly now, but:

Spoiler



Yes, that works. Now what does 1/sinx equal?
sonofdot
Too tired/tipsy too work it all out properly now, but:

Spoiler



Is this a real question or rhetorical?

assuming its a genuine question..

Spoiler

Swayum
Yes, that works. Now what does 1/sinx equal?


so then I would get xcosecx which I could do by parts, but I can't be bothered to do that now :p:
Reply 1236
Hmm... I think this is one of that 0af(x)dx=0af(ax)dx\displaystyle \int_0^a f(x) dx = \int_0^a f(a-x) dx jobs

sonofdot
so then I would get xcosecx which I could do by parts, but I can't be bothered to do that now :p:


Kinda tough integral though, doesn't evaluate in elementary functions
SimonM
A little easy again

Spoiler



Random trivia: (ab)\begin{pmatrix} a \\ b \end{pmatrix} is not the same thing as (ab)\displaystyle \left( \frac{a}{b} \right). The latter is something called the Jacobi symbol.
Zhen Lin
Random trivia: (ab)\begin{pmatrix} a \\ b \end{pmatrix} is not the same thing as (ab)\displaystyle \left( \frac{a}{b} \right).


Doh
SimonM
Hmm... I think this is one of that 0af(x)dx=0af(ax)dx\displaystyle \int_0^a f(x) dx = \int_0^a f(a-x) dx jobs



Kinda tough integral though, doesn't evaluate in elementary functions



Yep that's the way forward (that's how the teacher expected us to do it atleast)

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