Can u find ????????

1.Can you find the 10 th no. of this series ......

1, 2, 5, 10 , 17 ,................

Ans. : 82

Hint : ( it goes like this : 1st : 0^2 +1

2nd : 1^2+1 ...........................n th term :(n-1)^2+1 )

2. How do you switch the values of 2 variables , generally with the help of a third ......

For example : A=2 , B=3 ...and to swap them ....get a variable C

C<- A

A<-B

B<-C

and A has B' s value , B has A's value.........

So can you do the same switch without C ????????????

Hint : A=A+B

B=A-B

A=A-B

Facts :

We all know that the famous Ancient Greek Mathematician Pythagoras was the first person to prove the very famous Pythagorean Theorem named after the master himself , which states that the square of the hypotenuse of any triangle is equal to sum of the squares of the other two sides ..............but did you know that this great Mathematician was also one of the founders of music .....................He and his disciples found , for the first time that vibrating strings produce harmonious tones when the ratios of the lengths of the strings were altered by whole numbers.....Thus they invented the first Musical Instument on Earth !!!!!!!!! Is'int it amazing !!!!!!!!!!!