Найдите значение других трех основных тригонометрических функций ...

Дмитрий

1) pi/2 < a < pi, поэтому sin a > 0, cos a < 0cos a = -√6/4; cos^2 a = 6/16sin^2 a = 1 - cos^2 a = 1 - 6/16 = 10/16; sin a = √10/4tg a = sin a / cos a = (√10/4) : (-√6/4) = -√10/√6 = -√5/√3 = -√15/32) 0 < a < pi/2, поэтому sin a > 0, cos a > 0sin a = √2/3; sin^2 a = 2/9cos^2 a = 1 - sin^2 a = 1 - 2/9 = 7/9; cos a = √7/3tg a = sin a / cos a = (√2/3) : (√7/3) = √2/√7 = √14/73) 3pi/2 < a < 2pi, поэтому sin a < 0, cos a > 0cos a = 15/17; cos^2 a = 225/289sin^2 a = 1 - cos^2 a = 1 - 225/289 = 64/289; sin a = -8/17tg a = sin a / cos a = (-8/17) : (15/17) = -8/15