1. cos^2 a + sin^2 a = 1
cos^2 a = 1 - sin^2 a = 576 / 625
cos a = 24 / 25
2. cos^2 a + sin^2 a = 1
cos^2 a = 81/ 100
cos a = 9 / 10
3.cos^2 a + sin^2 a = 1
sin^2 a = 49 / 65
sin a = 7/ sqrt(65)
tg = 7 / sqrt(65) / (-4) / sqrt(65) = - 1 , 75
4. cos^2 a + sin^2 a = 1
sin^2 a = 9/ 10
sin a = 3 / sqrt(10)
tg a = 3 / sqrt(10) / 1 / sqrt(10) = 3
5. cos^2 a + sin^2 a = 1
cos^2 a = 1/10
cos a = 1/sqrt(10)
tg a = 3 / sqrt(10) / 1 / sqrt(10) = 3