Question

If the second term of GP is 2and sum
of its infinte
terms be 8 then find the first term
​

Answer 1

Step-by-step explanation:

ANSWER

General term rth term of

G.P=arn−1

⇒ ar=2

Infinite sum =1−ra=8

⇒ a=8−8r

⇒ r2=8−8r

⇒ 2=8r−8r2

⇒ 4r2−4rH=0

⇒ 4r2−2r−2rH=0

⇒ (2r−1)2=0

⇒ r=21

⇒ a=8−4=4

Answer 2

Answer:

a=4

Step-by-step explanation:

second term=2

a×r=2 (a is 1st term)(r is common ratio)

a/(1-r) = 8

a=8-8r

r=2/a

a=8-(16/a)

a^2 - 8a +16=0

(a-4)^2=0

a=4