Odpowiedzi

2010-02-04T11:44:21+01:00
(tgα + 1/tgα)² = (sin/cos + cos/sin)² = (sin²/sincos + cos²/sincos)² =
( 1/sincos)² = 1/(1-cos²)cos² = 1/ (1 -(½)²)(½)² = 1 / (1-¼)*¼ = 1/ ¾ *¼ =
1/3/16 = 16/3 = 5 1/3