is 2 and 5 both are underoot
i think a=5+√2, otherwise it would have written as a=√7, so if i consider a=5+√2
then 1/a=1/(5+√2)
and 1/a can be written as (5-√2)/(5+√2)(5-√2)=(5-√2)/23
so now a+1/a=5+√2+(5-√2)/23=115+23√2+5-√2=120+22√2=2(60+11√2)

Answers

  • Brainly User
2014-05-28T20:05:36+05:30
If a=√ 2+ 5, then find a +1/a
solution:
       a + 1/a = √(2+5)+1/
√(2+5)  
                 BY Cross Multiplication , we get
              =√(2+5)√(2+5) +1/ √(2+5)
              
=√(2+5)²+1/√(2+5)
                =2+5+1/
√(2+5)
               = 8/√(2+5)

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