the sum fo 4th and 8th term =22and the product of 2nd and 6th term =33.Find AP?
Answers
Given,
☛ sum of 4th term and 8th term = 22
==> a + 3d + a + 7d = 22
==> 2a + 10d = 22
==> a + 5d = 11 ...(1), also, It is the 6th term)
Also,
☛ product of 2nd term and 6th term = 33
==> ( a + 5d ) * (a + d) = 33
==> 11(a + d) = 33
==> a + d = 3
==> d = 3 - a ...(2)
Putting d = 3 - a in (1)
==> a + 5(3 - a) = 11
==> a + 15 - 5a = 11
==> -4a = -4
==> a = 1 ...(3)
Putting a = 1 in (2)
==> d = 3 - a
==> d = 3 - 1
==> d = 2 ...(4)
A.P = a , a + d, a + 2d, a + 3d, ...
A.P = 1 , 3, 5, 7, 9, ...
As we know that,
4th term = first term +3rd term
similarly,
8th term = first term + 7th term
Therefore,
(first term+3rd term)+(first term+7th term) = 2first term+10th term
= 2(first term+5th term)
= 2×6th term
=226th term
= 22/2
=11
6th term × 2nd term = 33
11×2nd term = 33
2nd term = 33/11= 3
6th term= first term+5th term
2nd term= first term+First term
11-3= (first term+5th term)-(first term+first term)
8= 4th term
1 term = 8/4=2
ap= 1,3,5,7,9,11,13,15,17,..............
Hope it helps you,
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