89 Racionalize as seguintes frações. a) sqrt ((16)/(4))= b) sqrt ((1)/(7))= c) sqrt ((26)/(4))= d) sqrt ((26)/(3))=

a) $$\sqrt {\frac {16}{4}} = \sqrt {4} = 2$$

b) $$\sqrt {\frac {1}{7}} = \frac {1}{\sqrt {7}} = \frac {1}{\sqrt {7}} \cdot \frac {\sqrt {7}}{\sqrt {7}} = \frac {\sqrt {7}}{7}$$

c) $$\sqrt {\frac {26}{4}} = \frac {\sqrt {26}}{2}$$

d) $$\sqrt {\frac {26}{3}} = \frac {\sqrt {26}}{\sqrt {3}} = \frac {\sqrt {26}}{\sqrt {3}} \cdot \frac {\sqrt {3}}{\sqrt {3}} = \frac {\sqrt {78}}{3}$$