function rad2deg(a) = a*180/PI;
function deg2rad(a) = a*PI/180;
function csc(a) = 1/sin(a);
function sec(a) = 1/cos(a);
function cot(a) = 1/tan(a);
function rsin(a) = sin(rad2deg(a));
function rcos(a) = cos(rad2deg(a));
function rtan(a) = tan(rad2deg(a));
function rcsc(a) = 1/sin(rad2deg(a));
function rsec(a) = 1/cos(rad2deg(a));
function rcot(a) = 1/tan(rad2deg(a));
function rasin(x) = deg2rad(asin(x);
function racos(x) = deg2rad(acos(x);
function ratan(x) = deg2rad(atan(x);
function sinh(a) = (exp(a)-exp(-a))/2;
function cosh(a) = (exp(a)+exp(-a))/2;
function tanh(a) = (exp(a)-exp(-a))/(exp(a)+exp(-a));
function csch(a) = 2/(exp(a)-exp(-a));
function sech(a) = 2/(exp(a)+exp(-a));
function coth(a) = (exp(a)+exp(-a))/(exp(a)-exp(-a));