Question

determine:
cos 585°

sen (-45°)

sen 45 Pi/2

Answer 1

cos(585°) = cos(360° + 225°) = cos(225°) = cos(180° + 45°) = –cos(45°) = –√2/2

sen(–45°) = sen(360° – 45°) = –sen(45°) = –√2/2

sen(45π/2) = sen(44π/2 + π/2) = sen(22π + π/2) = sen(π/2) = 1