Find the differential dy and use it to evaluate dy for the given values of x and dx:

Question

Find the differential dy and use it to evaluate dy for the given values of x and dx: y = (x + 1/x − 1) , x = 2, dx = 0.05

Answer 1

Is this y = (x+1)/(x-1) or y= x + (1/x) -1 ?!

If it is y = (x+1)/(x-1), then dy = - 2/(x-1)^2 dx, and therefore: dy(x=2) = -0.1.

If it is y= x + (1/x) -1 , then dy= 1 - 1/x^2, and therefore dy(x=2)= 0.0375.