series and sequences, i need help!?

The first one means the first digit of the series is -19. Every digit after the first is the previous digit +8. For example, a[1]=-19, so for a[1

k+1] when k=1, then a[1+1]=a[1]+8 or a[2]=-19 + 8 a[2]=-11

Second one means for ever digit i, from the bottom to top, 1-4 in this case, plug in i and add. So for this it would be:

[(4*-1 - 3)(5*-1 -5)]+[(4*0 - 3)(5*0 -5)]+[(4*1 - 3)(5*1 -5)]+[(4*2 - 3)(5*2 -5)]+[(4*3 - 3)(5*3 -5)]+[(4*4 - 3)(5*4 -5)]=x Or you could just use the formula [n(a[1]+a[n])]/2 with first and last digits.

Third one you want n to be2,16 . . .. Observe tha pattern each n pairing is the number n^3 * 2, so the summation equation is E[n=1][sup 6] 1/(n^2 * 2)

P.S. I really hate guys that take top spot by not answering the question and coming back to edit.

a(sub1) means the first term of a sequence

a(sub2) means the second term of a sequence.

a(subn) means the nth term of a sequence

a(subn+1) means the number after the nth term of a sequence

a(sub1) = -19 means first term is -19

a(subk+1) = a(subk) + 8

To find the next term

Plug in k=1

a(sub1+1) = a(sub1) + 8

You already know a(sub1) = -19

a(sub2) = -19 + 8 = -11

The pattern continues.

2) Evaluating series

The Weird E means to find a sum

The number on the bottom of the E = first term of the sequence when you plug it into the equation.

In your example, plug in -1 into the equation next to the E to get the first term.

Do this for all integers between -1 and 4, including -1 and 4.

Add your terms and that is your answer.

3)

1/ (2)(1^3) + 1 / (2)(2^3) + 1 / (2)(3^3) + 1 / (2)(4^3) + 1/ (2)(5^3) + 1/ (2)(6^3)

6

E [(1) / (2)(n^3)]

n=1