Question
Solve each equation on the interval $0 \leq \theta<2 \pi$.$$2 \cos ^{2} \theta-7 \cos \theta-4=0$$
Step 1
The equation is in the form of a quadratic equation, so we can factorize it as follows: \[2 \cos ^{2} \theta-7 \cos \theta-4=0\] This can be written as: \[(2\cos\theta + 1)(\cos\theta - 4) = 0\] Show more…
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