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Can someone help me with this, If A(-2,1), B(2,3) and C(-2,-4) are three points, then the angle between BAand BC is

If A(-2,1), B(2,3) and C(-2,-4) are three points, then the angle between BA and BC is

  • Option 1)

    \tan ^{-1}\left ( \frac{3}{2} \right )

  • Option 2)

    \tan ^{-1}\left ( \frac{2}{3} \right )

  • Option 3)

    \tan ^{-1}\left ( \frac{7}{4} \right )

  • Option 4)

    None

 
Answers (1)
124 Views
V Vakul

 

Angle between two lines (?) -

\tan \Theta = \frac{m_{2}-m_{1}}{1+m_{1}m_{2}}

- wherein

Here m_{1},m_{2} are the slope of two lines

 

 m_{1}=\frac{3-1}{2+2}=\frac{1}{2}

m_{2}=\frac{3+4}{2+2}=\frac{7}{4}

\tan \theta = \frac{\frac{1}{2}-\frac{7}{4}}{1+\frac{1}{2}\times \frac{7}{4}}

\frac{-10}{8+7}=\frac{-10}{15}=\frac{-2}{3}

So, acute angle \tan ^{-1}\left ( \frac{2}{3} \right )


Option 1)

\tan ^{-1}\left ( \frac{3}{2} \right )

This solution is incorrect

Option 2)

\tan ^{-1}\left ( \frac{2}{3} \right )

This solution is correct

Option 3)

\tan ^{-1}\left ( \frac{7}{4} \right )

This solution is incorrect

Option 4)

None

This solution is incorrect

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