1) Find all solutions θ 0° ≤ θ < 360° to the equation cos(2θ) = cosθ 2) Find the exact value of cot(795°) I have no idea how to do these, any help or tips?
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Originally Posted by alexcross 1) Find all solutions θ 0° ≤ θ < 360° to the equation cos(2θ) = cosθ 2) Find the exact value of cot(795°) I have no idea how to do these, any help or tips? For 1. you have to use some Double Angle identities. . So if This is a quadratic equation. Let So Case 1: Case 2: . Solve both cases for over the interval .
Originally Posted by alexcross 1) Find all solutions θ 0° ≤ θ < 360° to the equation cos(2θ) = cosθ 2) Find the exact value of cot(795°) I have no idea how to do these, any help or tips? 2. To evaluate this use the sum formula for tangent. . Can you go from here?
Originally Posted by alexcross 1) Find all solutions θ 0° ≤ θ < 360° to the equation cos(2θ) = cosθ 2) Find the exact value of cot(795°) I have no idea how to do these, any help or tips? 1. change to ... factor and solve for 2. 795 - 2(360) = 75 , a coterminal angle use your sum identities for cosine and sine, then evaluate.
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