Practicing Success
Solve for $ \theta: \cos^{2} - \sin^{2} \theta = \frac{1}{2}, 0 < \theta < 90^\circ$. |
45° 60° 30° 40° |
30° |
We are given, cos²θ - sin²θ = \(\frac{1}{2}\) { using, cos²θ - sin²θ = cos 2θ } So, cos 2θ = \(\frac{1}{2}\) { we know, cos 60º = \(\frac{1}{2}\) } So, 2θ = 60º θ = 30º
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