find the exact value of cos(2 arctan 4/3) without a calculator? please answer with details and explanations if you can.. i'm really confused and there's a test tomorrow. :(
Let θ = arc tan 4/3, then tan θ = 4/3 The scenario describes a right angled triangle with angle θ and the side opposite to θ is 4 and the side adjacent to θ is 3 and the hypotenus is 5. Thus cos θ = adj/hyp = 3/5 and sin θ = opp/hyp = 4/5
