MCQ
The angle between the two lines $y - 2x = 9$ and $x + 2y = - \;7,$ is .....$^o$
  • A
    ${60}$
  • B
    ${30}$
  • ${90}$
  • D
    ${45}$

Answer

Correct option: C.
${90}$
c
(c)These are perpendicular lines because ${m_1}{m_2} = (2)\left( {\frac{{ - 1}}{2}} \right) = - 1$

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