MyQuestionIcon

1

You visited us 1 times! Enjoying our articles? Unlock Full Access!

Sum of n Terms

If an A.P., i...

Question

If an A.P., is $a_{7} = 9$ , if $a_{1} . a_{2} . a_{7}$ is least, the common difference is

A

13 / 20

No worries! We‘ve got your back. Try BYJU‘S free classes today!

B

23 / 20

No worries! We‘ve got your back. Try BYJU‘S free classes today!

C

33 / 20

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

D

43 / 20

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Open in App

Solution

The correct option is C $33 / 20$
$a_{7} = a + 6 d$ (General term in AP : $a_{r} = a + (r - 1) d)$
$= 9$
$a = 9 - 6 d$
$f (d) = a_{1}, a_{2}, a_{6}$
$= (9 - 6 d) (9 - 6 d + d) (9 - 6 d + 6 d)$
$\frac{d}{d (d)} (f (d))$ minima
$\Rightarrow 9 [(- 6) (9 - 5 d) + (9 - 5 d) - 5] = 0$
$d = \frac{99}{60} = \frac{33}{20}$
option C is correct.

Suggest Corrections

thumbs-up

2

Similar questions

a_{i}, i = 1, 2, \dots, n

a_{7} = 9,

then the value of common difference of the A.P. such that

a_{1} \cdot a_{2} \cdot a_{7}

a_{1}, a_{2}, a_{3}, 5, 4, a_{6}, a_{7}, a_{8}, a_{9}

D = ∣ ∣ ∣ ∣ \begin{matrix} a_{1} & a_{2} & a_{3} 5 & 4 & a_{6} a_{7} & a_{8} & a_{9} \end{matrix} ∣ ∣ ∣ ∣

, then the value of

21 D

a_{1}, a_{2}, a_{3},

a_{n}

_____ are in A.P. such that

a_{4} - a_{7} + a_{10} = m

, then sum of first

13

terms of this A.P. is:

a_{1}, a_{2}, a_{3}, . ., a_{n}, . .

A . P

a_{4} - a_{7} + a_{10} = m,

then the sum of first

13

A . P

a_{1}, a_{2}, a_{3}

.... a_{n} are in A. P., then the common difference is--

View More

Join BYJU'S Learning Program

similar_icon

Related Videos

lock

Arithmetic Progression - Sum of n Terms

MATHEMATICS

Watch in App

explore_more_icon

Explore more

Standard XII Mathematics

Join BYJU'S Learning Program

CrossIcon