A) \[\frac{1}{2}\]
B) 0
C) 1
D) 2
Correct Answer: A
Solution :
\[\alpha =2\beta \] and \[\alpha +\beta ={{90}^{o}}\] \[\therefore \] \[\alpha ={{60}^{o}}\] and \[\beta ={{30}^{o}}\] \[\therefore \] \[{{\cos }^{2}}\alpha +{{\sin }^{2}}\beta ={{\cos }^{2}}{{60}^{o}}+{{\sin }^{2}}{{30}^{o}}\] \[=\frac{1}{4}+\frac{1}{4}=\frac{1}{2}\]You need to login to perform this action.
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