Question

rationalizati numitoruL
a)$\frac{5}{ 3\sqrt{10} }$
b)$\frac{8}{ \sqrt{6} + \sqrt{2} }$
ex7 Calculati
a)$\frac{1}{2 \sqrt{7} -1} + \frac{1}{ 2\sqrt{7}+1 }$
b)$( \sqrt{7+ \sqrt{33} } + \sqrt{7- \sqrt{33} } ) ^{-2}$

Answer 1

a)5/3√10=(5·3√10)/3²·√10²=15√10/9·10=15√10/90=√10/6
b)8/(√6+√2)=[8(√6-√2)]/(√6+√2)(√6-√2)=8(√6-√2)/(6-2)=8(√6-√2)/4=2(√6-√2)

a)=(2√7+1+2√7-1)/(2²·7-1)=4√7/27
b)= (√7+√√33+√7-√√33)⁻²=(2√7)⁻²=1/2√7=2√7/2²·7=2√7/28=√7/14