Tangent to a curve that passes through a given point

**y = -3.39x2 + 3.21x** Determine the positions on the curve (x,y), of all tangents that pass through the point (-4.87,67.22). Enter __none__ if no tangent exists. **ENTER THE LEFT-MOST TANGENT POINT (the one with the lowest x-value) IN THE **__FIRST__ BOX!

Round all values to FOUR decimal places, using the normal convention. Pad with zeros if necessary.

Example1: (-0.2305,2.3670)

Left-most tangent point (x,y) = [correct answer is (-11.8095,-510.6958)]

Right-most tangent point (x,y) = [correct answer is (2.0695,-7.8761)]

I've tried the approach you've listed here (http://www.mathhelpforum.com/math-he...tml#post351621) and it just doesn't seem to work for me. I was wondering if you could post a step by step approach so i can understand the process a little bit better.

Thank you

Billy