How many unique integer tuples are solutions for the equation x 2 + y 2 + z 2 = 3 ?
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yup.. aboves is the correct answer....i thought the same that x,y,z will be sure both 1 and -1 but i totally forgot the combination :-( .. thus i ticked 2 ... >:-( ahh feeling angry on myself !!!!!
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Did you know, I got a very bad dream about this XD, When I was sleeping, I dreamed about getting this question wrong again. My rating dropped down to 17XX (21XX in real life). I was angry, so I did 100 problems about number theory for hours! In my dream! Too bad I just did till 94 and my mom woke me up. :<
I made the same mistake... I'm really annoyed...
I feel very excited to do this problem. It's a problem that challenge me.
the given equation is a sphere . it has infinetly many points
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The approach is good Kamal but I guess you forgot about the integral solutions.
I want to know that why can't 2 and 3 ( and therefore -2 &-3) considered to be in the set..... e.g. let x be 1 and y be 2 then z will be 0. Then also the equation would be valid.....consider x to be 3 then y and z would be 0 which also can be a solution.....in that case..there can be many more solutions.. Please correct me if I am wrong.
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It is X^2 and not only X.
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DamnIT!..I used that but completely missed it..Me at fault
The answer of infinity should be removed as that is a correct answer in the complex plane
I used this method too!
Note that x , y , z ∈ { − 1 , 1 } , so there are 2 3 = 8 solutions.
− 2 > x , y , z > 2 because 2 2 > 3 and ( − 2 ) 2 > 3
x , y , z = 1 , − 1 , 0
Assuming without loss of generalities that x = 0 , 0 + y 2 + z 2 = 3 has no integer solutions.
Assuming WLOG that x = 0 and y = 0 , 0 + 0 + z 2 = 3 means that z = 3 , which is irrational.
x = 0
Thus, x , y , z , = 1 , − 1
Therefore, there are two combinations for each variable 2 × 2 × 2 = 8
i thought x, y and z must be different numbers
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I think a tuple in this instance is merely a list (of 3: x,y,z), so we needed to find unique combinations. Sadly I did not know this until I clicked 'discuss solution'! :-(
there are theree spots x, y and z to fit -1 and 1, which means we have 2 x 2 x 2 = 8 opitons in which -1 and 1 can be arranged into x, y, z to satisfy the given equation
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Since x 2 ≤ x 2 + y 2 + z 2 = 3 , hence ∣ x ∣ ≤ 3 . Since x is an integer, we have x = − 1 , 0 , 1 . However, if x = 0 , then we can't get y 2 + z 2 = 3 . Hence, x must be either 1 or -1. We have the same conclusion for y , z , thus x , y , z can be either 1 or − 1 .
Now there are 2 × 2 × 2 = 8 solutions.
( 1 , 1 , 1 )
( 1 , 1 , − 1 )
( 1 , − 1 , 1 )
( 1 , − 1 , − 1 )
( − 1 , 1 , 1 )
( − 1 , 1 , − 1 )
( − 1 , − 1 , 1 )
( − 1 , − 1 , − 1 )