Show that the equation of the straight line through the origin angle `varphi` with the line `y=m x+b\ i s y/x=(m+-t a nvarphi)/(1+-m\ t a nvarphi)`

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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