Arithmetic Progression

The product of n positive numbers is unity, then their sum is

If in a PQR, sin P, sin Q, sin R are in AP, then

The sum of first 9 terms of the series is

Let be consecutive terms of an arithmetic progression with common difference , and let be consecutive terms of another arithmetic progression with common difference , where For each , let be a rectangle with length , width and area If , then the value of is ___

Let be consecutive terms of an arithmetic progression with common difference , and let be consecutive terms of another arithmetic progression with common difference , where For each , let be a rectangle with length , width and area If , then the value of is ___