equation of tangent to ellipse in parametric form

Equation of Tangent to Ellipse \(x^2\over a^2\) + \(y^2\over b^2\) = 1 : (a) Point form : The equation of tangent to the given ellipse at its point (\(x_1, y_1\)) is  \(x{x_1}\over a^2\) + \(y{y_1}\over b^2\) = 1. Note – For general ellipse replace \(x^2\) by \(xx_1\), \(y^2\) by \(yy_1\), 2x by \(x + x_1\), […]