Exercise: Fibonacci number Check, if a number i is part of the Fibonacci sequence.

Fibonacci Number Detector

def is_fibonacci?(i)
  fib1 = 0
  fib2 = 1
while  fib1 <= i 
  fib1, fib2 = fib2, fib1 + fib2
end
  if fib1 == i
  return true
else
  return false
  end
end


def is_fibonacci?(i)
  a,b=0,1
    until b >= i
        a,b=b,a+b
        return true if b == i
    end
end