I'm finding it hard to do geometry proofs.

I can handle analytical proofs, but the vector and deductive proofs are way over my head...

 

How do you guys approach these types of proof?

Can you provide a specific example?

Well, just really anything in particular.

 

ie. Prove that if 25 is subtracted from the square of an odd integer greater than 5, the resulting number is always divisible by 8.

Originally posted by NSX

Well, just really anything in particular.

 

ie. Prove that if 25 is subtracted from the square of an odd integer greater than 5, the resulting number is always divisible by 8.

 

Proof by induction agogo

Originally posted by MrL_JaKiri

 

Proof by induction agogo

 

Well, our teacher wants us to do it deductively...

now lets try:

2n+1>5

n>2

(2n+1)^2-25/8

(2n+1+5)*(2n+1-5)/8

(2n+6)*(2n-4)/8

now n is an even number greater than 2 and 2n+6 and 2n-4 are also even numbers and their multiplication is also even when you divide even by even you get an integer from this the number given is diviseable by 8.

no body seems to reply to this thread and to point to me that my proof is not true, thanks (-: