Respuesta :
Given
[tex]\Sigma_{n=1}^\infty15(-4)^n[/tex]
The first 10 partial sums are as follows:
[tex]S_1=\Sigma_{n=1}^{1}15(-4)^n=15(-4)=\bold{-60} \\ \\ S_2=\Sigma_{n=1}^{2}15(-4)^n=\Sigma_{n=1}^{1}15(-4)^n+15(-4)^2 \\ =-60+15(16)=-60+240=\bold{180} \\ \\ S_3=\Sigma_{n=1}^{3}15(-4)^n=\Sigma_{n=1}^{2}15(-4)^n+15(-4)^3 \\ =180+15(-64)=180-960=\bold{-780} \\ \\ S_4=\Sigma_{n=1}^{4}15(-4)^n=\Sigma_{n=1}^{3}15(-4)^n+15(-4)^4 \\ =-780+15(256)=-780+3,840=\bold{3,060} \\ \\ S_5=\Sigma_{n=1}^{5}15(-4)^n=\Sigma_{n=1}^{4}15(-4)^n+15(-4)^5 \\ =3,060+15(-1,024)=3,060-15,360=\bold{-12,300}[/tex]
[tex]S_6=\Sigma_{n=1}^{6}15(-4)^n=\Sigma_{n=1}^{5}15(-4)^n+15(-4)^6 \\ =-12,300+15(4,096)=-12,300+61,440=\bold{49,140}[/tex]
The rest of the partial sums can be obtained in similar way.
[tex]\Sigma_{n=1}^\infty15(-4)^n[/tex]
The first 10 partial sums are as follows:
[tex]S_1=\Sigma_{n=1}^{1}15(-4)^n=15(-4)=\bold{-60} \\ \\ S_2=\Sigma_{n=1}^{2}15(-4)^n=\Sigma_{n=1}^{1}15(-4)^n+15(-4)^2 \\ =-60+15(16)=-60+240=\bold{180} \\ \\ S_3=\Sigma_{n=1}^{3}15(-4)^n=\Sigma_{n=1}^{2}15(-4)^n+15(-4)^3 \\ =180+15(-64)=180-960=\bold{-780} \\ \\ S_4=\Sigma_{n=1}^{4}15(-4)^n=\Sigma_{n=1}^{3}15(-4)^n+15(-4)^4 \\ =-780+15(256)=-780+3,840=\bold{3,060} \\ \\ S_5=\Sigma_{n=1}^{5}15(-4)^n=\Sigma_{n=1}^{4}15(-4)^n+15(-4)^5 \\ =3,060+15(-1,024)=3,060-15,360=\bold{-12,300}[/tex]
[tex]S_6=\Sigma_{n=1}^{6}15(-4)^n=\Sigma_{n=1}^{5}15(-4)^n+15(-4)^6 \\ =-12,300+15(4,096)=-12,300+61,440=\bold{49,140}[/tex]
The rest of the partial sums can be obtained in similar way.
Find 10 partial sums of the series. (Round your answers to five decimal places.)
∞
15 /(−4)n
Do calculations based on answer above (i.e. 15/(-4)^1 + 15/(-4)^2+...
1
-3.75000
Correct: Your answer is correct.
2
-2.81250
Correct: Your answer is correct.
3
-3.04688
Correct: Your answer is correct.
4
-2.98828
Correct: Your answer is correct.
5
-3.00293
Correct: Your answer is correct.
6
-2.99927
Correct: Your answer is correct.
7
-3.00018
Correct: Your answer is correct.
8
-2.99995
Correct: Your answer is correct.
9
-3.00001
Correct: Your answer is correct.
10
-3.00000
Correct: Your answer is correct.
Graph both the sequence of terms and the sequence of partial sums on the same screen.
WebAssign Plot WebAssign Plot
WebAssign Plot WebAssign Plot
Correct: Your answer is correct. (The one converging near -3, black dots)
Is the series convergent or divergent?
convergent
Correct: Your answer is correct.
If it is convergent, find the sum. (If the quantity diverges, enter DIVERGES.)
set up calculations to determine convergence (geometric)
a/1-r
a=15/-4 , r=1/-4
-3
Correct: Your answer is correct.