Made easy work book

Question

How to solve T (n)=T (sqrt n)+ n

Answer 1

The answer is theta(n) ?

Comments

Ans  is theta(log log n)

Answer 2

How answer can be theta(log(log n))

Comments

In workbook ans is mentioned as theta(log (logn))
Actually i am also getting  ans as theta (n)

Answer 3

Workbook answer is notoriously wrong. May be this helps

https://www.quora.com/What-is-the-complexity-of-recurrence-relation-T-n-2T-root-n-+n/answer/Daniel-R-Page

https://www.quora.com/What-is-the-complexity-of-t-n-t-%E2%88%9An-+n/answer/Daniel-R-Page

https://www.reddit.com/r/askmath/comments/4hzrzt/why_is_tn_tsqrtn_n_in_on/