Thank you for registering.

One of our academic counsellors will contact you within 1 working day.

Please check your email for login details.
MY CART (5)

Use Coupon: CART20 and get 20% off on all online Study Material

ITEM
DETAILS
MRP
DISCOUNT
FINAL PRICE
Total Price: Rs.

There are no items in this cart.
Continue Shopping

1. Find the arithematic progression whose third term is 16 and seventh term exceeds its fifth term by 12? 2. If an A.P consists of n terms with first term a and nth term l show that the sum of the mth term from the beginning and the mth term from the end is (a+l)?

1. Find the arithematic progression whose third term is 16 and seventh term exceeds its fifth term by 12?


2. If an A.P consists of n terms with first term a and nth term l show that the sum of the mth term from the beginning and the mth term from the end is (a+l)?


 


 


 


 


 


 


 


 


 

Grade:10

1 Answers

bharathteja p
74 Points
9 years ago

1. nth term can be given by a+(n-1)d

so, when n=3, a+2d=16.......................(1)

also when n=5 and n=7,

a+6d-a-4d=12

so 2d=12

d=6

now, from (1)

a=4

so the AP is 4, 10, 16, .....

 

 

2. mth term from beginning is a + (m-1)d

mth term from the end is  l - (m-1) d

a + (m-1)d + l - (m-1) d ( according to given condition )

= a+(m-1)d + l - (m-1)d

= a+ l

= hence proved.

Think You Can Provide A Better Answer ?

Provide a better Answer & Earn Cool Goodies See our forum point policy

ASK QUESTION

Get your questions answered by the expert for free