What do I need to write in f2 (u1, u2) so that I do not have the error : Undefined function or variable 'ETA'.

( this program is MATLAB )

Editor - C:\Users\Unnun\Downloads\f1.m f1.m X f2.m X targil.m X function cout 11 (2) load('data.mat'); fout = u2; Sf1(u2) 1 f1.m xf2.m Xtargil.m TyRZM X + function fout = f2 (ul, u2) load('data.mat.'); 1 40; n 100; A pi/10000; g 9.81; tout=g- (ETA* ((ul (end)-1)^0.8) *u2 (end))/(m*ul (end) )-(Gl*ul (end) *A)/(m* 1); 3 1 - f2(u1,u2) + f1.m f2.m targil.m X clear clc 2 format compact 3 format short 9 4 load('data.mat'); 5 h = 0.1; 6- t = 0; 1=40; m=100; A=pi/10000; g=9.81; 8 ul = 0; 9 u2 = 0; 0- Llwhile ul