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| 1. |
If sin theta + 2cos theta = 1 prove that 2sin theta - costheta = 2 |
| Answer» (sinθ + 2cosθ)2 = 12(sinθ + 2cosθ)2 + (2sinθ – cosθ)2 = 1 + (2sinθ – cosθ)2\xa05sin2θ + 5cos2θ = 1 + (2sinθ – cosθ)25 - 1 = (2sinθ – cosθ)2root4 = 2sinθ – cosθor, 2sinθ – cosθ = 2. | |