\\ => tg \alpha +1=4(1-tg \alpha) \\ tg \alpha +1=4-4tg \alpha \\ 5tg \alpha=3 \\ tg \alpha= \frac{3}{5} " alt="tg( \alpha + \pi /4)= \frac{tg \alpha +tg \pi /4}{1-tg \alpha tg \pi /4}= \frac{tg \alpha +1}{1-tg \alpha }=4=> \\ => tg \alpha +1=4(1-tg \alpha) \\ tg \alpha +1=4-4tg \alpha \\ 5tg \alpha=3 \\ tg \alpha= \frac{3}{5} " align="absmiddle" class="latex-formula">
