Question 1: If , prove that:

Answer:

Hence proved.

Answer:

Question 3: If , then show that:

are also in A.P.

Answer:

Hence proved.

Hence proved.

Answer:

ii) From i) since

Question 5: If , then prove that:

Answer:

Answer:

we get

Question 7: Show that and are consecutive terms of an A.P., if

Answer:

.

and are consecutive terms of an A.P.