1.

7. Evaluate: (4 / Cot² 30°) + (1 / sin² 60° ) - cos² 45°

Answer»

Step-by-step EXPLANATION:

We KNOW that,

\cot(30)  =  \sqrt{3}

\sin(60)  =  \frac{ \sqrt{3} }{2}

\cos(45)  =  \frac{1}{2}

The QUESTION,

\frac{4}{  \cot(30) \times  \cot(30)   }  +  \frac{1}{ \sin(60) \times  \sin(60)  }  - ( \cos(45)  \times  \cos(45) )

=  \frac{4}{ { \sqrt{3} }^{2} }  +  \frac{1}{  { (\frac{ \sqrt{3} }{2} )}^{2}  }  -   { \frac{1}{2} }^{2}

=  \frac{4}{3}  +  \frac{4}{3}  -  \frac{1}{4}

=  \frac{29}{12}



Discussion

No Comment Found

Related InterviewSolutions