Originally Posted by

**vane505** Hi, and thank you for your response.

I'm not sure if I understand you correct. You mean that sqrt.(6) is a never-ending decimal right?

I probably wasn't clear with my problem, or . I can get the correct answer, but I don't know how to calculate/convert the result so that it shows (sqrt(6) + sqrt(2))/4 instead of 0.965925......

I know how to calculate cos(45*-30*) = cos45*cos30*+sin45*sin30* = =0.965925......

This is how the problem is solved in the book:

cos(45* - 30*)= (1/sqrt(2))(sqrt(3)/2) + (1/sqrt(2))(1/2) =

= (sqrt(3) + 1)/(2sqrt(2)) = sqrt(2)(sqrt(3) + 1)/ = (sqrt(6)+sqrt(2))/4

My issue is that I don't know how to rewrite the cos45*cos30*+sin45*sin30* into (1/sqrt(2))(sqrt(3)/2) + (1/sqrt(2))(1/2)

and so on.

I'm sorry if my explanation is bad. I haven't studied much math before.

Again, appreciate help!