Question

Log2(√7+√3)+log2(√7-√3)

Answer 1

$log_2( \sqrt{7} + \sqrt{3})+log_2 ( \sqrt{7} - \sqrt{3})=log_2(\sqrt{7} + \sqrt{3}) ( \sqrt{7} - \sqrt{3})= \\ =log_2(7-3)=log_24=2$

Formule folosite:

$log_ax+log_ay=log_axy \\ (a+b)(a-b)=a^2-b^2 \\ log_ax=y \ =\ \textgreater \ a^y=x$