Quiz

This is a screenshot from AL Rachels's site

Marko,

These are legitimate concerns from the administrators of your site. However, these concerns are unfounded. Indeed, the Formulas plugin has existed since 2010, and it has always been properly maintained, updated, and even improved over the years. It is installed in nearly 2000 sites in universities and educational institutions worldwide. It is widely agreed to be the best plugin for creating numerical questions in the fields of sciences, technology, engineering, and basic mathematics. Installing the Formulas plugin, which can be done easily and quickly, would provide your institution with a very useful tool for improving its teaching.

Here are some explanations about the code.

# t: theta, the root we are seeking.
# Depending on the problem, you may want to adjust this value
# in order to get a convergent solution.
# Initial value of theta:
t = 0;  

# Small increment used to calculate numerically the
# derivative of the function from eq.(1):
# del: delta
del = 0.0001;

# You can increase the number of iterations
# in order to get a more precise result:
for (i:[0:20]) {

# Eq.(4a):
  psatp = 610.5*exp(17.269*t/(237.3+t));

# Eq.(4b):
  psatn = 610.5*exp(21.875*t/(265.5+t));

# Select eq.(4a) or eq.(4b):
  psat = t >= 0 ? psatp : psatn ;

# Eq.(2):
  p = phi*psat;

# Eq.(3):
  x = Mv/Md*p/(p0-p);

# Eq.(1) evaluated at t:
# ft: f(t)
  ft = x*hv + (x*c + cd)*t - h;

# Eq.(1) evaluated at t+del:
# ftd: f(t+delta)
  td = t + del;
  ftd = x*hv + (x*c + cd)*td - h;

# Numerical approximation of the derivative of ft at t:
# fpt (f prime t): f'(t)
fpt = (ftd-ft)/del;

# Newton's method.
# New value of t:
  tn = t-(ft/fpt);
  t = tn;
}