Math Nerd

[Kahuna]

Please explain to be how:

2 Times the Square root of 2 can equal 2 3/4 (11/4 as an improper fraction)

I had an arguement with my dad about, I was looking throw my text book and have no idea how it gets that answer.

 

[MiniKirk]

This isn't going to be much help but,

I multiplied the 4 through the equation and got that 8 times the squal root of 2 equals 11.313. So therefore 2 times the square root of 2 equals 11.3/4 or 113/40 whatever the right way to write it is. So my guess it's a typo, i'll ask around here (as I haven't done that sort of Maths in 2 years and there are people that have done it more recently) but I doubt i'll get a different answer.

Good luck with it.

 

[red+black]

A common approximation for the square root of 2 is 99/70.

So 2 x 99/70 = 198/70 = 11.3/4 ~ 11/4

I'm not sure what the whole point of this is though. The answer should be expressed as a decimal not a fraction.

 

[fugsy]

1.4142135623730950488016887242097 x itself = 2

2 x 1.4142135623730950488016887242097 = 2.828427124746190097603377448418 = Close enough to 2 3/4 for my liking.

Windows Calculator you star !

 

[The Great Gabsby]

Please explain to be how:

2 Times the Square root of 2 can equal 2 3/4 (11/4 as an improper fraction)

It can't. The square root of 2 is an irrational number and when you multiply an irrational number by a rational (in this case 2) you get back another irrational number, i.e. a number that cannot be expressed in fraction form. Therefore, it is impossible for 2*sqrt(2) to be exactly equal to 11/4, however i think you will find that 11/4 is a reasonable approximation to 2*sqrt(2).

 

[BomberGal]

It can't. The square root of 2 is an irrational number and when you multiply an irrational number by a rational (in this case 2) you get back another irrational number, i.e. a number that cannot be expressed in fraction form. Therefore, it is impossible for 2*sqrt(2) to be exactly equal to 11/4, however i think you will find that 11/4 is a reasonable approximation to 2*sqrt(2).

I showed my math nerd friend this, and he agreed with the above post.

He said:

The square root of 2 is provably irrational, therefore anything involving root 2 cannot be expressed as a fraction with integers.

I should have known myself that root 2 is irrational.

 

[RoosterLad]

i think its 17

 

[Lucev23]

Lock in 17 thanks Eddie