cos(65 degrees)=sqrt(1+cos130/2)
true or false
please explain why and how it is either true or false. My instant gues is that it is true because cos^2 x=1+cos(2x)/2
and from that the equation given will fit into that expression.

Question

cos(65 degrees)=sqrt(1+cos130/2)
true or false
please explain why and how it is either true or false. My instant gues is that it is true because cos^2 x=1+cos(2x)/2
and from that the equation given will fit into that expression.

rizags · Answer

Can you use a calculator or is it not allowed?

cutiecomittee123 · Answer

No, but I was right about it being true and my reasoning also made sense. Thank you though:) I kinda just posted this for validation.

rizags · Answer

Ah. No problem!