Posted by TRIG HELP on Monday, November 12, 2012 at 7:32am.
in this case you must use brackets or else the statement is false
LS = cosx/(1+sinx) + (1+sinx)/cosx
= cosx/(1+sinx) + (1+sinx)/cosx
= ( cosx(cosx) + (1+sinx)(1+sinx) )/(cosx(1+sinx))
= (cos^2 x + 1 + 2sinx + sin^2 x)/(cosx(1+sinx))
= (1 + 1 + 2sinx)/(cosx(1+sinx))
= 2(1+sinx)/(cosx(1+sinx))
= 2/cosx
= 2secx
= RS