Recent content by hew

I think i may have solved it. But do tell me if its wrong. 5!=5*4*3*2*1 and is therefore congruent to 0 mod 10 because of the 5 and 2. so that means that all of the other factorials greater than 5 will also be congruent 0 mod 10. Therefore the remainder will come from adding 1!+2!+3!+4! which...

Homework Statement prove that 1!+2!+...+n! is not a square if n>=4 Homework Equations The Attempt at a Solution in the previous part I had to prove that a sqare cannot end in 2,3,7,8 and did this by working in mod10. Do you use this to prove the question? I have written n as 10q+r...

Homework Statement decide if sqrt2 + sqrt5 +sqrt7 is rational or irrational, with proof Homework Equations The Attempt at a Solution i assumed that it was rational, the equation =r sqrt2 + sqrt 5=r- sqrt7 7 + 2sqrt10=r^2 + 7 -2r*sqrt7 2sqrt10=r^2 -2r*sqrt7 could i have a hint...

wow, i thought you somehow had to prove it. Thanks

Homework Statement prove that it is possible that an irrational number raised to another irrational, can be rational. you are given root2 to root2 to root2 Homework Equations The Attempt at a Solution i have shown that root2 to root2 to root2 is rational, but would appreciate a...