Respuesta :
Answer: [tex]\displaystyle \sum_{k=1}^{n}2(-6)^{k-1}[/tex]
The first term is a = 2. The common ratio is r = -6. You start off with 2 and multiply each term by -6 to get the next term.
eg: 2*(-6) = -12 ---> -12*(-6) = 72 etc etc
If you want the series summation to go on forever, then replace the 'n' up top with the infinity symbol [tex]\infty [/tex]
Note: Because |r| < 1 is not true (r < 1 in this case), this means that the series diverges.
The first term is a = 2. The common ratio is r = -6. You start off with 2 and multiply each term by -6 to get the next term.
eg: 2*(-6) = -12 ---> -12*(-6) = 72 etc etc
If you want the series summation to go on forever, then replace the 'n' up top with the infinity symbol [tex]\infty [/tex]
Note: Because |r| < 1 is not true (r < 1 in this case), this means that the series diverges.
Answer:
[tex]\displaystyle \sum_{k=1}^{n}2(-6)^{k-1}[/tex]
Step-by-step explanation:
we have to write the sum using summation notation of the following series:
2-12+72-432+...
which could also be written as:
2+(-12)+72+(-432)+...
We observe that first term=2
second term=2×-6
Third term=2×-6×-6
Fourth term=2×-6×-6×-6
nth term=[tex]2\times (-6)^{n-1}[/tex]
Hence, the series sum= [tex]\displaystyle \sum_{k=1}^{n}2(-6)^{k-1}[/tex]