Try A) 60 degrees; 1/2. Your answer was incorrect because cos(60 degrees) is 1/2, cos(30 degrees) is square root 3 /2 not 1 or square root 2 /2
Not necessarily. You could have done your multiplication wrong. Or in some cases, yes, you could have to use another skill. For example, you can't solve an optimization problem with addition, you need some calculus skills under your belt.
Oof I’m not quite sure how to do that
