а) tg1°·tg2°·tg3°·...·tg89° = tg(1°+2°+3°+...+89°) = tg(4005°) = tg(360°+360°+360°+360°+5°) = tg5° = 0.0875
б) ctg2°·ctg4°·ctg6°·...·ctg178° = ctg(2°+4°+6°+...+178°) = ctg(178179/2) = ctg(15901) = ctg(36044+1) = ctg1° = 1.
а) tg1°·tg2°·tg3°·...·tg89° = tg(1°+2°+3°+...+89°) = tg(4005°) = tg(360°+360°+360°+360°+5°) = tg5° = 0.0875
б) ctg2°·ctg4°·ctg6°·...·ctg178° = ctg(2°+4°+6°+...+178°) = ctg(178179/2) = ctg(15901) = ctg(36044+1) = ctg1° = 1.