- MathguyLv 51 month agoFavorite Answer
I won't solve them for you, you need to learn how... so here is a hint for each part.
1. calculate cos (a) and sin (ß) by using pythagorean Thm,
( sin@)^2 + (cos@)^2 = 1 so you can find cos a, then sin ß
For example cos a = √ [ 1 - ( sin a )^2 ] , I get 20/ 29
2. Decide the sign, + or - on each angle a is in Quadrant I so cos a is also +
3. Now that you have sine, cosine for each angle use the trig identities...
sin ( a + ß ) = sin a cos ß + cos a sin ß
cos( a - ß) = cos a cos ß + sin a cos ß
tan ( a - ß) = [ tan a - tan ß ] / [ 1 + tan a tan ß ]
It's a lot of multiplication and simplifying, but you need the practice to be able to do it on a test.