Show that the line `a^2x+a y+1=0` is perpendicular to the line `x-a y=1` for all non zero real values of `adot`

Explanation

The given lines are `a^2x + ay + 1 = 0 … (1)`


` x − ay = 1 … (2)
`

Let m1 and m2 be the slopes of the lines (1) and (2).


` m_1.m_2 = - (a^2)/a×1/a = -1 `


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