# --00--

Members

11

## Posts posted by --00--

### Integral of tan

Please could you tell me how to integrate tan^3[x] without integration by parts.

i know that tan^2x = sec^2 x - 1

### Logarithms

thanks. ive worked it out now...

### Logarithms

This is probably really easy for all you guys, but I can't see the answer:

Given that log 2 = 0.3, show that log 5 = 0.7

### 1?

^assuming that is correct^

31131122211311123113321112131221123113112211121312211213211321322112311311222113311213212322211211131221221113222123211211131211121311121321123113112221231221322113112211

### I saw a nice proof today

And it does have one use: I got an offer from a uni based on an interview where I had to prove that (2^0.5) was irrational' date=' and I used that proof .

Ollie[/quote']

How exactly did you use this proof because if you use this proof for 2^0.5, then in Fermat's last theorem, n=2, which doesn't contradict Fermat's last theorem.

### Square root of 0.9

the thing is, this was set as a sort of 'brainteaser' question, so i was wondering if there was a simple, almost 'sneaky' way of doing it...

### 1?

11131221131211131231121113112221121321132132211331222113112211

- i think...!

### Square root of 0.9

Does anybody have any ideas on how to work out [imath]\sqrt{0.9}[/imath] without a calculator (to approx 10 d.p.)?

I know there are a few methods for working out for working out square roots by hand, but i was wondering if there was a cleverer/easier way of doing it.

### Hehe this is funny!

why does women = time * money and not women = time + money?

- that's true. I originally saw this proof for 'teletubbies', for which it worked, because they were the PRODUCT of time and money (hence multiplication)...

### Derive pie

$\pi=\frac{diameter}{circumfrence}$

That is all.

actually' date=' [math']\pi=\frac{circumference}{diameter}[/math]

### 0 x infinity = -1 ?

the gradient of a horizontal line = 0

the gradient of a vertical line = infinity

but the product of the gradients of perpendicular lines is -1

so does that mean that 0 x infinity = -1 ???

... or is there something in the proof for the product of the gradients equalling -1 which excludes it for these values?

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