Verified answer

a) tan 60° = sin 60°/cos 60° = ((sqrt3)/2)/1/2 = sqrt(3)

b) sin(90° - thêta) = cos (thêta) = sin(90°- 60°) = sin30° =

cos 60° =1/2

d) cot60° = 1/tan60° = 1/sqrt(3) = 1/sqrt(3) * sqrt(3)/sqrt(3)

= (sqrt(3))/3

c) cos(90° -thêta) = sin (thêta) = cos(90°-60°) = cos30° =

sin60° = (sqrt3)/2

a) tan 60 = sin60/cos60 = √3/2 / 1/2 => √3/2*2.1= √3

d) cotan 60 = 1/tan60= 1/√3

b) sin 30=cos60=1/2

c) cos30= sin60=√3/2