for number 2)

left hand side

= sec(u) + csc(u)cot(u)

= 1/cos(u) + [1/sin(u)]*[cos(u)/sin(u)]

= 1/cos(u) + [cos(u)/(sin(u))^2]

= [(sin(u))^2 + (cos(u))^2]/[cos(u)*[sin(u)]^2]

= 1/[cos(u)*[sin(u)]^2]

= sec(u)*[csc(u)]^2

= right hand side

sorry about the bad syntax. hope it makes sense!