Question 1187014
<br>
Use parentheses!!!<br>
1.  Is it sin(a/2) = {{{sin(a/2)}}}?  Or is it (sin(a))/2 = {{{(sin(a))/2}}}<br>
2.  This one, "cos11𝜋/12cos𝜋/12" can be interpreted many different ways.  Since you say it is a product, you probably mean (cos(11pi/12))*(cos(pi/12)) = {{{(cos(11pi/12))*(cos(pi/12))}}}<br>
But we tutors should not need to guess what it is that you write in your posts....<br>
Re-post, showing the problems clearly.<br>
NOTE!!! One problem per post, so post them separately.<br>