<![CDATA[Calculating Equations of Tangent Lines to a Cubic Function through an External Point]]>
https://help.geogebra.org/topic/calculating-equations-of-tangent-lines-to-a-cubic-function-through-an-external-point
Thu, 20 Sep 2018 11:05:50 +0000Wed, 19 Sep 2018 20:50:29 +0000Zend_Feed<![CDATA[You need to do this algebraically, using the steps you usually follow when doing it on paper. So if P is the (unknown) point in which the tangent touches your cubic f, the tangent through P has equation y - y(P) =f'(x(P)) (x - x(P)). Then you must tell your tangent to pass through A, and solve this condition to find the point of contact P, and finally create line AP. See also https://help.geogebra.org/t...]]>
https://help.geogebra.org/topic/calculating-equations-of-tangent-lines-to-a-cubic-function-through-an-external-point#comment-246610
Thu, 20 Sep 2018 09:36:20 +0000<![CDATA[and tangent(P,f) gives the tangent to f through (x(P),f(x(P)))]]>
https://help.geogebra.org/topic/calculating-equations-of-tangent-lines-to-a-cubic-function-through-an-external-point#comment-246622
Thu, 20 Sep 2018 11:05:50 +0000