Question

If the 6th term of an ap is 2 then the value of common difference of an ap, which makes the product a1a4a5 least

Answer 1

Answer: c

Step-by-step explanation:Let a be the first term and x be the common difference

of the A.P. Then a x + 5 2 = = & a x 2 5 -

Let P a = = 1 4 a a5 a] ] a x + + 3 4 g g a x

= ] ] 2 5 --- x x g g 2 2 ]2 xg = 2

5 1 x x7 16 4 x 3 2 ^ h - + - +

Now , . dx

dP 0 x 5

8

3

2 = = &

Clearly, dx

d P2 > 0 2

for x 3

2 =

Hence P is least for x 3

2 = .

Answer 2

Answer:

hope my answer helps you