Question

how does sin(-150)-tan(840)×cos(330) end up as 1? I either end up with 0 or -1.​

Answer 1

Answer:

sin(-150)-tan(840)×cos(330)  =  1

Step-by-step explanation:

sin(-150)-tan(840)×cos(330)

sin(-150) = -sin(150) = -sin(180-30) = -sin(30) = -1/2

tan(840) = tan(840-(2*360)) = tan (120) = -sqrt(3)

cos(330) = cos(360-330) = cos(30) = sqrt(3)/2

= (-1/2) - (-sqrt(3)) * sqrt(3)/2

= -1/2 - -3/2

= -1/2 + 3/2

= (-1 + 3)/2

= 2/2

= 1