Expression 2: sine left parenthesis, "x" , right parenthesis left brace, negative StartFraction, pi Over 2 , EndFraction less than or equal to "x" less than or equal to StartFraction, pi Over 2 , EndFraction , right bracesinx−π2≤x≤π2
2
Expression 3: arc cosine left parenthesis, "x" , right parenthesisarccosx
3
Expression 4: cosine left parenthesis, "x" , right parenthesis left brace, 0 less than or equal to "x" less than or equal to pi , right bracecosx0≤x≤π