Show that the equation of the passing through the origin and making an angle `theta`with the `y=m x+c`is `y/x=+-(m+tantheta)/(1-mtantheta)`.

Explanation

Let the equation of the line passing through the origin be `y=m_1 x`


If this line makes an angle of θ with the line `y=mx+c`, then angle θ is given by


`tan theta = |(m_1-m)/ (1+m_1m)|`


`=> tan theta = | ((y/x) -m) /(1+y/x m)|`


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