Currently there are only 3 parameters describing the entire ss coordinate system in terms of x and y: a y_0, a stretch in x, and a slope in y. We see that this simplistic model is too rigid to capture the observed trend that the slit length shrinks slightly with x. So we need an x^2 term coefficient.
Currently there are only 3 parameters describing the entire
sscoordinate system in terms ofxandy: ay_0, a stretch in x, and a slope in y. We see that this simplistic model is too rigid to capture the observed trend that the slit length shrinks slightly with x. So we need anx^2term coefficient.