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| 1. |
If 2 sin square theta - cos square theta = 2 then,find the value of theta |
| Answer» Given:\xa0{tex}2sin^2\\theta-cos^2\\theta=2{/tex}⇒\xa0{tex}2(1-cos^2\\theta)-cos^2\\theta=2{/tex}\xa0{tex}[\\because sin^2\\theta+cos^2\\theta=1]{/tex}⇒{tex}2-2cos^2\\theta-cos^2\\theta=2{/tex}{tex}\\Rightarrow 2-3cos^2\\theta=2{/tex}{tex}\\Rightarrow -3cos^2\\theta=2-2{/tex}⇒\xa0{tex}-3cos^2\\theta=0{/tex}{tex}\\Rightarrow cos^2\\theta=0{/tex}{tex}\\Rightarrow cos\\theta=0{/tex}{tex}\\Rightarrow cos\\theta=cos90°{/tex}{tex}\\Rightarrow \\theta=90°{/tex}\xa0 | |