Answer:
-1280.
Step-by-step explanation:
f(n + 1) = -2 f(n):
As function of 1 = 160, function of 2 = -2 * 160 = -320.
function of 3 = -320 * -2 = 640 and
= function of 4 = 640 * -2 = -1280.
The value of n is y and the value of m is z
Cosine Rule again:-
cos A = (9^2 - 6^2 - 14^2) / (-2*6*14)
= 0.8988
m < A = 26 degrees
It is asking you to find the sum of k^2 - 1 from k=1 to k=4. Since that is only 4 numbers, calculating the sum by hand wouldn’t be that bad.
(1^2 - 1) + (2^2 - 1) + (3^2 - 1) + (4^2 - 1) = 26
The easier way to find the sum is to use a few simple formulas.
When we have a term that is just a constant c, the formula is c*n.
When we have a variable k, the formula is k*n*(n+1)/2.
When we have a squared variable, the formula is k*n*(n+1)*(2n+1)/6.
In this case, we have a squared variable k^2 and a constant of -1.
So plug in n=4 to the formulas:
4*5*9/6 - 1*4 = 26
The answer is 26
Step-by-step explanation:
None of these,
a(under root),a, a(square)
this is the correct answer
