This function is used for input variable screening. It is shown above in its only two active variables. A small error term ε ~ N(0, 0.05 2) is added to the response ...

Therefore since the trig equation we are solving is sin and it ... but negative this means that we will be in the two quadrants where the sine function is negative - the third and fourth quadrants.

Many students think they've solved a trig equation when they get one answer ... this means that we will be in the two quadrants where the sine function is negative, ie the third and fourth ...