Maths Problems for a thought

[desiredusername]

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If you've entered this section, you must love maths. Why not share the love for maths?


Post interesting maths problem solving questions. =D

[humphdogg]

let a = b.
multiply both sides by a.
a^2 = ab
add a^2 to both sides.
2a^2 = a^2 + ab
subtract 2ab from both sides.
2a^2 - 2ab = a^2 - ab
take out a^2 - ab as a common factor.
2(a^2 - ab) = 1(a^2 - ab)
divide through by a^2 - ab.
2 = 1
subtract 1 from both sides.
1 = 0

QED.

[watatank]

Originally Posted by humphdogg

let a = b.
multiply both sides by a.
a^2 = ab
add a^2 to both sides.
2a^2 = a^2 + ab
subtract 2ab from both sides.
2a^2 - 2ab = a^2 - ab
take out a^2 - ab as a common factor.
2(a^2 - ab) = 1(a^2 - ab)
divide through by a^2 - ab.
2 = 1
subtract 1 from both sides.
1 = 0

QED.

but you've said a^2 = ab ---> a^2 - ab = 0 hence you cant do that step.

[undalay]

Originally Posted by watatank

but you've said a^2 = ab ---> a^2 - ab = 0 hence you cant do that step.

He knows that :P
You can't prove 0=1
Humphdogg was just mucking around.

[Roguedeth]

0.9999999999999 = 1

[EvozRule]

Originally Posted by Roguedeth

0.9999999999999 = 1

¬¬

0.999999999 ~ 1

[EvozRule]

Originally Posted by watatank

but you've said a^2 = ab ---> a^2 - ab = 0 hence you cant do that step.

well actually since he is using two pronumerals, he can do that step...i know, i know, pointless statement for a pointless arugment.

[desiredusername]

Originally Posted by 3unitz

i like this integral
∫ dx / (x^3 + 2x + 3)

(x^4 / 4) + [(2x^2)/2] + 3x + C

= ( 45 surd 5) /8 + (111/ 8) + C

Is that correct?

[jyu]

No, try partial fractions

[denominator]

what is the last digit of this number?

333^444

(a) 1
(b) 3
(c) 7
(d) 9

[lolokay]

Originally Posted by denominator

what is the last digit of this number?

333^444

(a) 1
(b) 3
(c) 7
(d) 9

a) 1.

it repeats every 4 powers with 1 being the last digit of 333^0

[lyounamu]

Originally Posted by aMUSEd1977

Prove 0 = 1

I can't.

Originally Posted by denominator

what is the last digit of this number?

333^444

(a) 1
(b) 3
(c) 7
(d) 9

None. It's a maths error.

I am joking. It's 1 as lolokay already said.

[lolokay]

Originally Posted by lyounamu

None. It's a maths error.

lol

[field5]

Actually 0.9' does = 1

Let x = 0.9'
Therefor 10x = 9.9'
Therefor 9x= 9
Therefore x = 1

[gcspsp]

Originally Posted by field5

Actually 0.9' does = 1

Let x = 0.9'
Therefor 10x = 9.9'
Therefor 9x= 9
Therefore x = 1

How can you subtract 'x' from either side if 'x' is only on one side?