Find the indicated sum. Show your work.
4 k=1 (-1)^k(k+11)
Inbetween the 4 and k , Theres a backwards 3 sign
That's a sigma
4
∑ (-1)^k (k+11)
k=1
= (-12)+(13)+(-14)+(15)
= 2
Thank you :)
To find the indicated sum of the given expression, we need to substitute different values of "k" into the expression and add up the results.
The expression given is: (-1)^k(k+11)
First, we substitute k = 1:
(-1)^1(1+11) = (-1)(12) = -12
Next, we substitute k = 2:
(-1)^2(2+11) = (1)(13) = 13
Continuing this process, we substitute k = 3:
(-1)^3(3+11) = (-1)(14) = -14
As requested, we continue this pattern until we reach k = 4.
Finally, we substitute k = 4:
(-1)^4(4+11) = (1)(15) = 15
To find the sum, we add up the values we obtained:
(-12) + 13 + (-14) + 15 = 2
Therefore, the indicated sum of the expression is 2.