Math game
Math game
Time for another forum game. Rules are the same as the other silly games, only this time it's about hard math questions. You can also show how each question are solved if you could.
Let's start off with an easy one. Convert the following to its simplest form:
sqrt((x-y)(x+y)+y2)
Good luck
Let's start off with an easy one. Convert the following to its simplest form:
sqrt((x-y)(x+y)+y2)
Good luck
Last edited by resir014 on Sat Nov 06, 2010 1:17 pm, edited 1 time in total.
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"When I have finished explaining you will understand less."
"When I have finished explaining you will understand less."
Re: Math game
Nice idea
((x-y)(x+y)+y2)0.5 = x0.5+y
((x-y)(x+y)+y2)0.5 = x0.5+y
Mujisan // Zunzelina // Lönnby Idrottspark // More tracks
Re: Math game
Wrong.AleksiNir wrote:Nice idea
((x-y)(x+y)+y2)0.5 = x0.5+y
Updated the question for a little hint.
@resir014 | GWR Stats | My GeneRally Stuffs | Twitter
"When I have finished explaining you will understand less."
"When I have finished explaining you will understand less."
Re: Math game
sqrt((x-y)(x+y)+y2)
√(x²-y²+y²)
√(x²)
√(x²-y²+y²)
√(x²)
Re: Math game
Everything's gonna be fine.. until someone wants to divide by zero.
Re: Math game
What about...
sqrt((x-y)(x+y)+y2)
√(x²+y²)
sqrt((x-y)(x+y)+y2)
√(x²+y²)
Last edited by AleksiNir on Sat Nov 06, 2010 1:52 pm, edited 2 times in total.
Mujisan // Zunzelina // Lönnby Idrottspark // More tracks
Re: Math game
√((x-y)(x+y)+y²)=√(x²-xy+xy-y²+y²)=√x²=|x|
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Re: Math game
Guys, you depress me. When I see what all I forgot in past 5-7 years from leaving high school.
Otherwise I think, that match exercises have often more than one transcription of same solution, so this maybe isn't best thing for a game (it can cause confusions and misunderstandings).
I would say Mr.J and Herbal are both right, btw.
Otherwise I think, that match exercises have often more than one transcription of same solution, so this maybe isn't best thing for a game (it can cause confusions and misunderstandings).
I would say Mr.J and Herbal are both right, btw.
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Re: Math game
LOL ... I'm scared. It's been many years...
Now, just know that I know nothing...
but, this little game is cool.
Now, just know that I know nothing...
but, this little game is cool.
ECOlogic Racing Team
Re: Math game
What I was looking for is "x", but that is acceptable for now.Mr.J wrote:sqrt((x-y)(x+y)+y2)
√(x²-y²+y²)
√(x²)
Your turn.
@resir014 | GWR Stats | My GeneRally Stuffs | Twitter
"When I have finished explaining you will understand less."
"When I have finished explaining you will understand less."
Re: Math game
Text question.
Resi wants to know how high a church is. So he measure that the angle of the sun and the ground is 20°. Then he measures that the church's shadow is 195m. How high is the hurch?
Resi wants to know how high a church is. So he measure that the angle of the sun and the ground is 20°. Then he measures that the church's shadow is 195m. How high is the hurch?
Re: Math game
This time I can't be wrong.
I made the answer in paint
I made the answer in paint
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Last edited by AleksiNir on Sat Nov 06, 2010 3:30 pm, edited 1 time in total.
Mujisan // Zunzelina // Lönnby Idrottspark // More tracks
Re: Math game
Almost. You had to use tangens
tg 20°=x/195 m => x=tg 20°*195 m=70,97 m
tg 20°=0,3639
tg 20°=x/195 m => x=tg 20°*195 m=70,97 m
tg 20°=0,3639
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Re: Math game
Herbal wrote:Almost. You had to use tangens
Mujisan // Zunzelina // Lönnby Idrottspark // More tracks
Re: Math game
Yes Herbal.
Cosine is adjacent/hypotenuse
Cosine is adjacent/hypotenuse
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Re: Math game
Guys, if you want help with your homeworks, you can say it directly, not mask it behind a game. otherwise I guessed well, that Herbal will be fast.
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Re: Math game
OK, this will be a bit harder, but not that much.
We have on a Descartes-coordinate system (the usual x,y,z ) 3 points, A, B, and C.
A(5,13,1)
B(1,1,-5)
C(3,7,-8)
Tell me, what's the area of ABC triangle.
Hint: if needed, use the Car editor to set up points, just divide them by ten to handle them ^^)
We have on a Descartes-coordinate system (the usual x,y,z ) 3 points, A, B, and C.
A(5,13,1)
B(1,1,-5)
C(3,7,-8)
Tell me, what's the area of ABC triangle.
Hint: if needed, use the Car editor to set up points, just divide them by ten to handle them ^^)
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Re: Math game
AB = √(5-1)²+(13-1)²+(1+5)²=√16+144+6=√166
BC = √(1-3)²+(1-7)²+(-5+8)²=√4+36+3=√43
AC = √(5-3)²+(13-7)²+(1+8)²=√4+36+81=√121=11
Area = √[(166+43+121)²-2(121²+43²+166²)] * 0,25
√[(330)²-2(14641+1849+27556)] * 0,25
√[108900 - 88092 ] * 0,25
√20808 * 0,25 =~ 144,25 * 0,25 =~ 36,062
Good idea, I hope I didn't do any mistake
BC = √(1-3)²+(1-7)²+(-5+8)²=√4+36+3=√43
AC = √(5-3)²+(13-7)²+(1+8)²=√4+36+81=√121=11
Area = √[(166+43+121)²-2(121²+43²+166²)] * 0,25
√[(330)²-2(14641+1849+27556)] * 0,25
√[108900 - 88092 ] * 0,25
√20808 * 0,25 =~ 144,25 * 0,25 =~ 36,062
Good idea, I hope I didn't do any mistake
Last edited by Darjo on Sat Nov 06, 2010 7:50 pm, edited 1 time in total.
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Re: Math game
My vector cross product calculations give: A = 1/2*|BA x BC| = 12*(10)^(1/2).
Re: Math game
Darjo wrote:AB = √(5-1)²+(13-1)²+(1+5)²=√16+144+6=√166
BC = √(1-3)²+(1-7)²+(-5+8)²=√4+36+3=√43
AC = √(5-3)²+(13-7)²+(1+8)²=√4+36+81=√121=11
=which equals to ~37,9473, which is true! Go ahead, Sikamies!Sikamies wrote:My vector cross product calculations give: A = 1/2*|BA x BC| = 12*(10)^(1/2).
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Re: Math game
Ok, next problem from probabilty theory:
Alfa and Bravo have a meeting at 6 pm.
Alfa arrives at random time between 6.00 pm and 6.20 pm (uniform probability distribution) and goes home after waiting 15 minutes if he has not seen Bravo.
Bravo, similarly, arrives at random time between 6.00 pm and 6.30 pm and goes home after waiting 10 minutes if he has not seen Alfa.
What is the probability that they meet?
Alfa and Bravo have a meeting at 6 pm.
Alfa arrives at random time between 6.00 pm and 6.20 pm (uniform probability distribution) and goes home after waiting 15 minutes if he has not seen Bravo.
Bravo, similarly, arrives at random time between 6.00 pm and 6.30 pm and goes home after waiting 10 minutes if he has not seen Alfa.
What is the probability that they meet?
Re: Math game
Argh, this is what I go on the Internet to get away from!
72.9%?
72.9%?
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Re: Math game
50%, they do meet or they don't
Re: Math game
That's correctbduddy wrote:72.9%?
( = 35/48 = ~0.729 )
Your turn