The square root of 34 is just sqrt(34), or if you're looking for a rounded decimal answer, about 5.83. The square root of -4/11:
[tex] \sqrt{ \frac{-4}{11} } \\
= \sqrt{ \frac{-1 * 4}{11} } \\
= \frac{2i}{ \sqrt{11} } \\
= \frac{2i\sqrt{11}}{11} [/tex]
The square root of 34 is an irrational number. The square root of -4/11 is an imaginary number, or nonreal complex number.