Question

The sum of 3 terms in an ap is 15 and the sum of the squares of the numbers is 58.find ap

Answer 1

Let the first three terms be a-d,a,a+d
Now,
a-d+a+a+d=15(given)
Therefore a=5
Now.
(a-d)^2 + a^2 +(a+d)^2=58 (given)
a^2+d^2-2ad+a^2+a^2+d^2+2ad=58
3a^2+2d^2=58
Put a=5,
Therefore d=(-2.9)
Thus the required numbers are
a-d=7.9
a=5
a+d= 2.1


Hope it helps you.....