calculate approximate derivative in matlab

Hi, I'm not sure where to begin translating the solution of this problem into a function in MATLAB.

approximate the derivative of the function y=log x at the point x=1 from the following table of numbers:

[Jan]

You can use the left, right or two-side quotient of differences: dx = (y - y0)/(x - x0).

The implementation is easy, but I don't want to solve your homework.

Answer 1

[Sam Chak]

Hi @Minh

Not sure if you are looking for this

syms x
y    = log(x)

y = 

dydx = diff(y)

dydx = 

However, please check the data in the Table because

log(1)

ans = 0

Else, you can approximate the derivative using this principle

so long as .

x = 0.98:0.02:1.02

x = 1×3

0.9800 1.0000 1.0200

y = [0.7739332 0.7651977 0.7563321]

y = 1×3

0.7739 0.7652 0.7563

dydx1 = (y(2) - y(1))/(x(2) - x(1))

dydx1 = -0.4368

dydx2 = (y(3) - y(2))/(x(3) - x(2))

dydx2 = -0.4433