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Question
State whether the following equation has a solution or not?
cos 2θ = `1/3`
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Solution
Given:
cos 2θ = `1/3`
This value, `1/3` lies between −1 and 1, and the cosine function can take any value in that range.
−1 ≤ `1/3` ≤ 1
So the equation: cos 2θ = `1/3`
has real solutions
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