Answer:
(a) u₃ = 71.8768 (b) u₁ = 0.6
Explanation:
given the recursive formula
= 2
² - 7
this allows any term in the sequence to be found by multiplying the square of the previous term by 2 ,then subtracting 7
(a)
u₃ = 2u₂² - 7 ← substitute u₂ = - 6.28
u₃ = 2(- 6.28)² - 7
= 2(39.4384) - 7
= 78.8768 - 7
= 71.8768
(b)
from the formula , we can obtain
u₂ = 2u₁² - 7 ← substitute u₂ = - 6.28 and solve for u₁
- 6.28 = 2u₁² - 7 ( add 7 to both sides )
0.72 = 2u₁² ( divide both sides by 2 )
0.36 = u₁² ( take square root of both sides )
=
, that is the positive value of u₁ is
0.6 = u₁