The figure above shows the curve C with equation:
???? = 2????3 + 3????2 ? 11???? ? 6
The curve crosses the ????-axis at the points ???? , ???? and ????(2,0). The tangent to ???? at ???? is the straight line ????1. The normal to ???? at ???? is the straight line ????2. The straight lines ????1 and ????2 meet at the point S.
3a) Find an equation of ????1. 3b) Show that ????????????? = 90°.