\[\boxed{\mathbf{1043.}}\]
\[0 < a < \frac{\pi}{4};\ \ \ 0 < \beta < \frac{\pi}{4};\]
\[\ \ a + \beta = \frac{\pi}{4}\]
\[1)\ (1 + tg\ a)(1 + tg\ \beta) = 2\]
\[1 + tg\ a + tg\ \beta + tg\ a\ tg\ \beta = 2\]
\[1 + tg\ (a + \beta)(1 - tg\ a\ tg\ \beta) +\]
\[+ tg\ a\ tg\beta = 2\]
\[1 + tg\frac{\pi}{4}(1 - tg\ a\ tg\ \beta) +\]
\[+ tg\ a\ tg\ \beta = 2\]
\[1 + 1 - tg\ a\ tg\ \beta +\]
\[+ tg\ a\ tg\ \beta = 2\]
\[2 = 2\]
\[Что\ и\ требовалось\ доказать.\]
\[2)\ (1 - ctg\ a)(1 - ctg\ \beta) = 2\ \]
\[1 - ctg\ a - ctg\ \beta +\]
\[+ ctg\ a\ ctg\ \beta = 2\]
\[1 -\]
\[- ctg\ (a + \beta)( - 1 + ctg\ a\ ctg\ \beta) +\]
\[+ ctg\ a\ ctg\ \beta = 2\]
\[1 + 1 - ctg\ a\ ctg\ \beta +\]
\[+ ctg\ a\ ctg\ \beta = 2\]
\[2 = 2\]
\[Что\ и\ требовалось\ доказать.\]