simplify cos60deg cos30deg-sin60degsin30deg

Question

anonymous · Answer

attachment

lgbasallote · Answer

hint $$\cos ( a + b) = \cos a \cos b - \sin a \sin b$$
does that help?

anonymous · Answer

yes but i got another one involving vector if you got a moment

lgbasallote · Answer

that seems very distant from this topic...

anonymous · Answer

never mind the vector could you give me some more information on simplifying the above expression

anonymous · Answer

if u dont kne that formula ...just subs values of cos 60 and cos 30  and sin

lgbasallote · Answer

like i told you...use that formula i gave...for example $$\cos(20) \cos (40) - \sin(20)\sin (40) \implies \cos (20 + 40) \implies \cos (60)$$

anonymous · Answer

ok i would like to say thank you and move on to a harder question, sin2A/1+cos2A

callisto · Answer

I would like to say please start a new post for a new question, thanks!

anonymous · Answer

ok