" Life is not a problem to be solved but a reality to be experienced! "
© Copyright 2013 - 2024 KUDO.TIPS - All rights reserved.
Ad2
(sinα + cosα)² - (sinα - cosα)² =
= sin²α + 2sinαcosα + cos²α - (sin²α - 2sinαcosα + cos²α ) =
= sin²α + 2sinαcosα + cos²α - sin²a + 2sinαcosα - cos²α = 2sinαcosα + 2sinαcosα=
= 4sinαcosα
można jeszcze tak:
2sinαcosα + 2sinαcosα = sin2α + sin2α = 2sin2α