t x (i)
cos –1 (sin x)
(ii)   
1
sin
tan
1
cos
x
x
− 



+

 (iii)   
1
1
2
sin
1
4
x
x
+
− 



+

Solution
(i)
Let f (x) = cos –1 (sin x) Observe that this function is defined for all real numbers