Question

2 part question here.

a) Find the slope of the tangent to the curve y = 1/((x)^(1/2)) at the point where x = a
b)Find equations of the tangent lines at the points (1,1) and (4,1/2)

I understand the idea behind f(a+h)-f(a)/h and taking the limit as h approaches 0, but I don't understand how to take the tangents in this case with the square root.

Thanks in advance for any assistance!