Question

przedstaw w prostszej postaci:

a) (1-sinalfa)(1+sinalfa)

b) sinalfa ctglafa

Answer 1

a)

(1-sinα)(1+sinα) = 1-sin²α = cos²α

                                                           (a-b)(a+b) = a²-b²

                                                           sin²α+cos²α = 1

 

b)

sinα · ctgα = sinα · cosα/sinα = cosα

Answer 2