1. The problem statement, all variables and given/known data Find the line tangent to the point 2pi/3 when x=cost y=sqrt3 cost. Also find the value of d2y/dx2 at the point given. 2. Relevant equations I found dy/dx to be -sqrt3 sint/ -sint. I found that to be just sqrt3. This matched what my calculator told me the slope was. The equation of the tangent is y=sqrt3 x or at least I think. I am having trouble with the second derivative. I believe that it is 0. When I applied the quotient rule to dy/dx I got sqrt3 sintcost-sqrt3 sintcost/sin2t. I then multiplied by dt/dx. Either way, the numerator is still 0. Am I right, on the right path, or completely wrong.