Q. Find all angles, 0∘≤θ<360∘, that satisfy the equation below, to the nearest tenth of a degree.cos2θ−2cosθ=0Answer: θ=
Factor equation: Factor the given equation cos2(θ)−2cos(θ)=0. We can factor out cos(θ) from both terms. cos(θ)(cos(θ)−2)=0
Solve for theta: Set each factor equal to zero and solve for theta.cos(θ)=0 and cos(θ)−2=0For cos(θ)=0, the angles where the cosine of theta is zero are 90∘ and 270∘.For cos(θ)−2=0, we add 2 to both sides to get cos(θ)=2. However, the cosine of an angle cannot be greater than 1 or less than −1, so there are no solutions from this part.
Compile solutions: Compile the solutions.The angles that satisfy the equation are 90∘ and 270∘.
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