Question 975996
A.
sin(240) + cos (120)
= sin (180+60) + cos(90+30)
= -sin(60) -sin(30)
= {{{-sqrt(3)/2 -1/2}}}
= {{{ -((sqrt(3)+1)/2)}}}

B. 
{{{2/sin^2(45) - 2/cos^2(30)}}}
= {{{2/(1/2) - 2/(3/4)}}}
=4-8/3
=4/3

C.
cos30 * tan 45
= {{{(sqrt(3)/2) * 1}}}