solve a system of nonlinear equations + partial derivatives

Question

Abdelhak BENKABA 2022-3-16

回答： Torsten 2022-3-16

Hello

I am a beginner in Matlab, I would like to solve a system of nonlinear equations which contains equations with partial derivatives

r=x^2+y^2+z^2+w^2

find x , y , z , w

dr/dx+dr/dy+dr/dz+dr/dw =0

((5.3)-(x+23.5))^2+((11.4)-(y+12.8))^2-18^2=0;

((5.3)-(z+7.3))^2+((11.4)-(w+6.7))^2-36=0;

((x+23.5)-(z+7.3))^2+((y+12.8)-(w+6.7))^2-36-18^2=0

Answer 1

Torsten 2022-3-16

I would like to solve a system of nonlinear equations which contains equations with partial derivatives

If you evaluate dr/dx, dr/dy, dr/dz and dr/dw, you get a fourth algebraic equation.

This system of 4 algebraic equations in 4 unknowns can be solved using "fsolve".