Evaluate (8 Sigma n-1)n.
Where 8 is on top and n-1 is on the bottom and n is on the right.
A) 36
B) 8***
C) 40
D) 24
At the bottom of the sigma I am sure it said n = 1 , not n-1
If so, then you want
1+2+3+4+5+6+7+8
which is easy to do in your head
certainly not 8 !
It says n-1. I will do it your way though since it makes the most sense to me. The equal sign must be squished or something.
To evaluate the given expression, (8 Σn-1)n, we can break it down step by step.
1. First, let's determine the value of Σn-1. Σ represents the summation symbol, and in this case, we are summing the values of n-1 as n takes on different values.
2. The range of n is not specified, so let's assume it starts from 1. Therefore, the values of n-1 will be 0, 1, 2, 3, ..., n-1.
3. To evaluate Σn-1, we add up all these values. Since the range is from 0 to n-1, we can use the formula for the sum of an arithmetic series:
Σn-1 = (n-1)(n-1+1)/2 = n(n-1)/2
4. Now, we substitute the value of Σn-1 into the original expression:
(8 Σn-1)n = (8 * (n(n-1)/2))n = 4n(n-1)
5. Finally, we simplify the expression by expanding the brackets:
4n(n-1) = 4n² - 4n
Now that we have simplified the expression, we can see that there is no fixed value given for n, so we can't determine the exact numerical value of the expression. The correct answer would be none of the options given.