b)
• `sin^2 A + cos^2 A = 1`
`<=> sin^2 A + 0,6^2 =1`
`<=> sin^2 A = 0,8`
• `tan A = (sinA)/(cosA) = 4/3`
• `cot A = 1/(tanA) = 3/4`
c) `tanA = 3 <=> (sinA)/(cosA) = 3 <=> sinA = 3cosA`
• `cot A = 1/3`
• `sin^2 A+cos^2 A =1`
`<=> (3cos^2 A) + cos^2 A=1`
`<=> 9cos^2 A+cos^2 A=1`
`<=> cosA = \sqrt10/10`
`=> sinA = (3\sqrt10)/10`
d) `cotA=2 <=> (cosA)/(sinA) = 2 <=> cosA = 2sinA`
• `tanA = 1/2`
• `sin^2A+cos^2 A=1`
`<=> sin^2 A + 4sin^2 A=1`
`<=> sinA = \sqrt5/5`
`=> cosA = (2\sqrt5)/5`
