Show that the equation of the tangent to the hyperbola at is .


At (x1, y1) : ⇒ b2x12 – a2y12 = a2b2


y – b = m(x – a)



a2y1y – a2y12 = b2x1x – b2x12


b2x1x – a2y1y = a2b2



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