Question

Find the AP if the sum of any three terms is 15 and the sum of square of last three terms is 58
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Answer 1

Answer:

let a-d, a ,a+d are three terms in AP

sum of three terms = 15

a-d+a+a+d =15

⇒3a=15

a=15/3

a= 5--(1)

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sum of the squares of the extremes = 58

(a-d)²+(a+d)²= 58

⇒2(a²+d²) =58

⇒a²+d²=58/2

⇒5²+d²= 29   [ from (1)]

⇒d² = 29-25

∴d²=4

d= 2 or -2

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required three terms are 

if a=5 , d= 2           

a-d, a, a+d

(5-2),5,(5+2)

3,5,7

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if a=5 , d=-2

[5-(-2)], 5, [5+(-2)]

7,5,3

Answer 2

Answer:

ANSWER 3,5,7

HOPE THAT HELPS