JCECE Engineering JCECE Engineering Solved Paper-2002

  • question_answer
    The angle between the pair of lines is given by the equation\[{{x}^{2}}+2xy-{{y}^{2}}=0\]is:

    A) \[\frac{\pi }{3}\]                                              

    B) \[\frac{\pi }{6}\]

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

    D)  \[0\]

    Correct Answer: C

    Solution :

    Key Idea: Angle between the pair of lines\[{{x}^{2}}+2xy-{{y}^{2}}=0\]is                 \[\theta ={{\tan }^{-1}}\frac{\sqrt{{{h}^{2}}-ab}}{a+b}\] Given pair of lines is                 \[{{x}^{2}}+2xy-{{y}^{2}}=0\] Here,     \[a=1,\,\,h=1,\,\,b=-1\] \[\therefore \]  \[\theta ={{\tan }^{-1}}\frac{\sqrt{1+1}}{1-1}={{\tan }^{-1}}(\infty )\] Note: If pair of lines is parallel, then \[{{h}^{2}}-ab=0\]


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