Find the nth tearm

-5 -2 3 10 19

Given :

The sequence is -5 , -2 , 3 , 10 , 19 .

To Find :

The nth term of the given sequence .

Solution :

Difference between first 2 terms :

-2 - ( -5 ) = 3    1 term

3 - ( -2 ) = 5     2 term    

10 - 3 = 7         3 term

19 - 10 = 9       4 term

From the above observation we can say that difference is increasing in odd number .

So, the nth term will be :

 for n greater than equal to 0.

Hence, this is the required solution.

The surface area for this case is given by:
 A = 2 * pi * r ^ 2 + 2 * pi * r * h
 Where,
 r: radius of the coins
 h: height of the coin stack.
 Substituting values we have:
 A = 2 * 3.14 * (1/2) ^ 2 + 2 * 3.14 * (1/2) * (100 * (1/8))
 A = 40.82 in ^ 2
 Note: the correct thickness of the coins should be 1/8 in.
 
 Jose will need 40.82 in ^ 2 to cover the stack of coins