Posted by T.Gracken on November 01, 2002 at 07:47:11:
In Reply to: Prove Trig posted by Ray on October 31, 2002 at 21:08:14:
: Help:
: Given: Angles A and B are in standard position.
: sin A = 1/2 and cos A>0
: tan B = 3/4 and sin B<0
: 1. Find exact value of: sec 15degree
: 2. Find exact vaule of: csc5pie/12
: 3. Prove: sin(0+60degree) -cos(0+30degree)=sin0
are you sure you know what you are being asked? the given conditions look like they are for separate problems. they have no bearing on the numbered problems.
as far as the numbered problems, just LOOK UP IN YOUR TEXT (or even online) the sum and difference formulas for trig functions.
along with the reciprocal identities, YOU can easily determine sec(15o) and csc(5pi/12) by rewriting
sec(45o-30o) and csc(i'll let you figure this one out)
as for #3, just evaluate each expression.