2. Questions Bank
  3. 10th Class
  4. Mathematics
  5. Introduction to Trigonometry

10th Class Mathematics Introduction to Trigonometry Question Bank Trigonometry

  • question_answer
    The product \[\mathbf{cos}\,{{\mathbf{1}}^{^{\mathbf{o}}}}\mathbf{cos}{{\mathbf{2}}^{\mathbf{o}}}\mathbf{cos}{{\mathbf{3}}^{\mathbf{o}}}\mathbf{cos}{{\mathbf{4}}^{\mathbf{o}}}.....\mathbf{cos18}{{\mathbf{0}}^{\mathbf{o}}}\]is equal to

    A) \[-1\]

    B) \[\frac{1}{4}\]

    C) 1

    D) 0

    Correct Answer: D

    Solution :

    (d): \[cos{{1}^{^{o}}}cos{{2}^{o}}cos{{3}^{o}}cos{{4}^{o}}.....cos{{180}^{o}}\] \[=0\left[ cos{{90}^{{}^\circ }}=9 \right]\]


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