Implicit differentiation.

Here's the problem:

"Consider the curve defined by the implicit equation $\displaystyle y+5cosy=x^2+2.$

a) Find $\displaystyle dy/dx$ in terms of x and y.

b) Find the equation of the tangent line at the point shown where x=2.

c) Find two positive values of x in the portion of the curve shown at which there is a vertical tangent line." (There's a picture here of the graph, given so that one could visually look to see where they think a vertical tangent line might be.) "Use calculus to find the values to 3 decimal places. You can use your calculator to solve the equation that must be true for a vertical tangent line."

Any help on how to solve these, please?