Odpowiedzi

2010-02-07T18:29:12+01:00
A)
(sinα + cos α )² + ( sin α - cos α)² = 2
L = sin²α +2 sin α cosα + cos²α + sin²α -2 sin α cos α + cos²α =
= 2* (sin²α + cos²α) + (2 sin α cos α - 2 sin α cos α) =
= 2 * 1 + 0 = 2 = P
b)
1/cosα - cos α = sin α * tg α
L = 1/cos α - cos²α/cos α = [1 - cos²α] / cos α = sin²α / cos α =
= sin α * [sin α/ cos α ] = sin α * tg α = P
gdy cos α ≠ 0