trigcos takes as argument an expression
containing trigonometric functions.
trigcos simplifies this expression with the formula :
sin(x)2+cos(x)2=1, tan(x)=sin(x)/cos(x) and
tries to rewrite the expression only with cosine.
Input :
^
4+cos(x)^
2+1)Output :
^
4-cos(x)^
2+2