1) -sin(pi/2)(2tan(pi/2) - cos(pi/6)= -(-1)(2undefined - sqrt(3)/2)= 2 + sqrt(3)/2
2) cot(pi/6)(sin(pi/3) - 3cos(pi/3)= sqrt(3)/(sqrt(3)/3) (sqrt(3)/2 - 3(-1/2))= 3 * (sqrt(3)/2 + 3/2)= 3sqrt(3) + 9/2
3) cos(pi/4)(2cot(pi/4) - 3sin(pi/6)= sqrt(2)(2/(sqrt(2)) - 3(1/2))= sqrt(2)(1 - 3/2)= sqrt(2)*(1/2)= sqrt(2)/2
1) -sin(pi/2)(2tan(pi/2) - cos(pi/6)
= -(-1)(2undefined - sqrt(3)/2)
= 2 + sqrt(3)/2
2) cot(pi/6)(sin(pi/3) - 3cos(pi/3)
= sqrt(3)/(sqrt(3)/3) (sqrt(3)/2 - 3(-1/2))
= 3 * (sqrt(3)/2 + 3/2)
= 3sqrt(3) + 9/2
3) cos(pi/4)(2cot(pi/4) - 3sin(pi/6)
= sqrt(2)(2/(sqrt(2)) - 3(1/2))
= sqrt(2)(1 - 3/2)
= sqrt(2)*(1/2)
= sqrt(2)/2