1) sint= -15/17 Pi< t < 3Pi/2 Найти: cost, tgt, ctgt 2) sin^2t -------------- + 1 = ?...

Question

1) sint= -15/17 Pi< t < 3Pi/2
Найти: cost, tgt, ctgt
2) sin^2t
-------------- + 1 = ?
cos^2t

Answer 1

Cost = - √(1 - Sin²t) = - √(1 - 225/289) = - √64/289 = - 8/17
tgt = Sint/Cost = - 15/17 : (- 8/17) = 15/8 = 1 7/8
ctgt = 1/tgt = 8/15
2) Sin²t/Cos²t + 1 = tg²t + 1 = (15/8)² + 1 = 225/64 + 1 = 289/64 = 4 33/64