Question

gente, me ajudem!!!!

Answer 1

a)
$\frac{ \sqrt{2} }{2}$
b)
$\frac{ \sqrt{5 + \sqrt{10} } }{5}$
c)
$\frac{6 + 2 \sqrt{2} }{7}$
d)
$7 - 4 \sqrt{3}$