Posted by Ruby on .
Approximate the square root of 64.3, y=x^(1/2). Starting point is the square root of 64.

college calc 
Reiny,
y = x^(1/2)
dy/dx = (1/2)x^(1/2)
dy = 1/(2√x) dx
when x = 64, dx = .3
dy = (1/2√64)(.3) = (1/16)(.3) = appr .01875
so √64.3 = 8.01875
actual √64.3 by calculator = 8.018729
error is .000022