\begin{array}{rll}
\left(\frac{-q}p\right)&=\left(\frac{-1}p\right)\left(\frac q p\right)=&\hbox{jer su kvadratni ostaci multiplikativni}\\
&=\left(\frac q p\right)=&\hbox{jer je $p\equiv 1\pmod 4$}\\
&=\left(\frac p q\right)&\hbox{prema teoremi o kvadratnoj recipro\v cnosti}\end{array}