Python Question; I've had this question on a test and I got it wrong. I have no idea which parts if any were correct of whether I'm on the right track. My answers are in bold and italics any help would be amazing

"Referring to the code below,

import scipy.optimize as sco

popt, pcov = sco.curve_fit(func, x, y, (1.5, 2., 1.3),

bounds=(( 1.e-3, 1.e-3, 1.e-3),

(np.inf, np.inf, np.inf) ))

What is the name (in the package) of the parameter that the tuple (1.5, 2., 1.3) specifies?

curve_fit

The method implemented by the curve_fit function may be specified by a str; 'lm', 'trf' or 'dogbox'. The default is 'lm'. Which method str will this specific call to the function utilise?

intercept estimation

What exception or warning would be raised if the covariance of the parameters cannot be estimated?

OptimizeWarning: Covariance of the parameters could not be estimated