math
posted by fanny on .
find the eqt. of tangent to the curve y=x^2+2x10.[ans:y=2x10]
but my ans is y=9. if im wrong could you show the calculation.

At what point along the curve is the tangent contact made?
Based upon the answer, it is where dy/dx = 2
dy/dx = 2x + 2 = 2, so x = 0 at the point of contact. That requires y = 10 at that point.
So y = 2x  10 is the answer IF you are talking about the line tangent to the curve at x = 0.
You omitted an important part of the problem statement. 
in the question it say: at the point where the curve cuts the yaxis