I am having some serious problems with this section. My book is no use to me. Thanks for all the help! It says: use the basic identities to change the expression to one involving only sines and cosines. Then simplify to a basic trigometric function.

1). (sinx)(tanx+cotx)

2). sinx-tan(x)cos(x)+ cos(pi/2-x)

3). sin(x)cos(x)tan(x)sec(x)csc(x)