wiz-icon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

If |x| < 1, then the sum of the series 1 + 2x + 3x2 + 4x3 + ....... will be

A
11x
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
11+x
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
1(1+x)2
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
1(1x)2
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
Open in App
Solution

The correct option is D 1(1x)2
This is an A.G.P.
Let S = 1 + 2x + 3x2+....
x.S=x+2x2+.....
Subtracting (1x)S=1+x+x2+......=11x
S=1(1x)2.
Aliter : Use S = [1+r1r×diff.ofA.P.]11r.

flag
Suggest Corrections
thumbs-up
0
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Arithmetic Geometric Progression
MATHEMATICS
Watch in App
Join BYJU'S Learning Program
CrossIcon