When a program lets the user know that an invalid choice has been made, this is known as: ?

You picked the corridor which led you here. if the guards find you, they're going to be really angry! what is the synonym of angry

Least square fit to polynomial write a function leastsquarefit3pol that solves a linear system of equations to find a least squares fit of a third order polynomial to an experimental data set given as two row arrays. the function leastsquarefit3pol must explicitly solve a set of linear equations and cannot use polyfit. there should be no restriction on the size of the problem that can be solved.

Which of the following is not a symptom of chronic fatigue syndrome