[WP-34S] DEG and RAD - diffs

[Paul Dale]

It isn't so much that a multiplication introduces such a large error, rather it introduces a small error which is then amplified by the subsequent functions.

Consider the gradient of the various functions at the points they are evaluated to get an idea of the magnitude of the error possible. For example, for an argument near zero, SIN will produce a greater error than COS simply because the function is steeper there. In degrees and gradians, 9 is reasonably close to zero. For radians it is heading towards one and a half times around the circle.

Also remember that there is a multiplication before and after each trigonometric function when not in radians. Each potentially introduces a small error.

Also, your result above for radians is completely wrong. It simply isn't possible for the final arcsine step to return a value greater than 2π.

- Pauli