The tangent line of a curve or a function can be obtained by taking the first derivative of the function given. In this case, the derivative of y=sqrt(x) is equal to y' = 0.5 x ^ -0.5. At point (1,1), y' is equal to 0.5. Using point slope form, the equation is y = 0.5x - 0.5 +1 = 0.5 x + 0.5