Practice problems/A challenging tangent line problem
From UBCMATH WIKI
For the following questions, consider the function y=f(x)=(x+2)2.
- Find the equations of all lines tangent to y=f(x) that pass through the point (1,1). Note that this point is not on the graph of f.
- Is there a point Q=(x1,y1) on the line y=x such that there is ONLY one tangent line to the curve y=f(x) passing through Q?
Justify your answer.