2. Questions Bank
  3. JEE Main & Advanced
  4. Mathematics
  5. Rectangular Cartesian Coordinates

JEE Main & Advanced Mathematics Rectangular Cartesian Coordinates Question Bank System of co-ordinates, Distance between two points, Section formulae

  • question_answer
    If the coordinates of vertices of \[\Delta OAB\] are (0,0) \[(\cos \alpha ,\,\sin \alpha )\] and \[(-\sin \alpha ,\,\cos \alpha )\] respectively, then \[O{{A}^{2}}+O{{B}^{2}}=\] 

    A) 0

    B) 1

    C) 2

    D) 3

    Correct Answer: C

    Solution :

    \[O{{A}^{2}}={{\cos }^{2}}\alpha +{{\sin }^{2}}\alpha =1\] and \[O{{B}^{2}}={{\sin }^{2}}\alpha +{{\cos }^{2}}\alpha =1\]. Hence\[O{{A}^{2}}+O{{B}^{2}}=1+1=2\].


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