10th Class Mathematics Introduction to Trigonometry Question Bank Case Based (MCQs) - Introduction to Trigonometry

  • question_answer
    The value of \[\tan S+\cot R\] is:

    A) \[\frac{9}{4}\]

    B) \[\frac{5}{3}\]

    C) \[\frac{2}{5}\]

    D) \[\frac{31}{15}\]

    Correct Answer: D

    Solution :

    We know the identity,            
    \[1+{{\tan }^{2}}S={{\sec }^{2}}S\,\,\,\Rightarrow \,\,\,\,\tan S=\sqrt{{{\sec }^{2}}S-1}=\sqrt{{{\left( \frac{\sqrt{34}}{3} \right)}^{2}}-1}\]
    [From part 1]
    \[=\sqrt{\frac{34}{9}-1}=\sqrt{\frac{25}{9}}=\frac{5}{3}\]
    Also, know the identity, \[1+{{\cot }^{2}}R=\cos e{{c}^{2}}R\]
    \[\Rightarrow \,\,\,\cot R=\sqrt{\cos e{{c}^{2}}R-1}=\sqrt{{{\left( \frac{\sqrt{29}}{5} \right)}^{2}}-1}=\sqrt{\frac{29}{25}-1}=\sqrt{\frac{4}{25}}=\frac{2}{5}\]
    \[\therefore \,\,\,\,\,\,\,\,\,\tan S+\cot R=\frac{5}{3}+\frac{2}{5}=\frac{25+6}{15}=\frac{31}{15}\]
    So, option [d] is correct.


You need to login to perform this action.
You will be redirected in 3 sec spinner