given : Y=e1/2LOG(1+TAN
X)
TAKE LOG ON BOTH SIDES.......U GT
LOG Y =I/2 LOG(SEC^2 X)
DIFF BOTH SIDES
1/Y DY/DX = 1/2 2.SECX.SECX.TANX/SEC^2 X
DY/DX = e1/2 LOG(SEC^2 X)TANX
TAKE THE SQ. OF SECX OUT OF LOG....1/2 AND 2 CANCELS.....THN APPLY THE BASE CHANGE PROPERTY OF LOG....i.e TAKE E IN LOG AND SECX DOWN.....
HERE'S UR ANSWER....
REPLY IF U DINT UNDERSTOOOD NY STEP...