2015年5月30日 · On the trig unit circle: sin 120 = sin (180 - 60) = sin 60 = sqrt3/2

show that sin 780 degree sin120 degree + cos240 degree sin390 degree = 1/2

2018年3月14日 · The value of sin 120.? Trigonometry. 1 Answer Umer F. Mar 14, 2018 ...

2016年7月15日 · Use trig identity: sin 2a = 2sin a.cos a sin 120 = 2sin 60.cos 60 Trig table --> sin 60 = 1/2 and cos 60 = sqrt3/2.

2016年6月26日 · How do you know if #sin 30 = sin 150#? How do you show that #(costheta)(sectheta) = 1# if #theta=pi/4#? See all questions in Trigonometric Functions of Any Angle

2014年10月24日 · Since sin2theta=2sin theta cos theta, we have sin120^circ=2sin60^circcos60^circ=2cdot sqrt{3}/2 cdot 1/2=sqrt{3}/2. I hope that this was helpful.

2015年7月10日 · sin120=sqrt(3)/2 cos120=-1/2 tan120=-sqrt(3) ctg120=-sqrt(3)/3 sec120=-2 csec120=(2sqrt(3))/3 To calculate sin120 and cos120 you can use the reduction formula, which says, that sin(180-x)=sinx and cos(180-x)=-cosx Rest of the functions can be calculated as: tanx=sinx/cosx ctgx=1/tanx secx=1/cosx csecx=1/sinx

2015年8月27日 · color(red)(sin(405) + sin(120) = (sqrt2+sqrt3)/2) > sin(405) = sin(360 + 45) The sine sum identity is: sin(A+B) = sinAcosB+cosAsinB ∴ sin(405) = sin(360)cos(45) + cos(360)sin(45) We can use the unit circle to work out the values.

sin 120 o. View Solution. Q2. Find the values of the following: sin 120 o. View Solution. Q3. Find the ...

2018年5月21日 · Find the value of sin 120°+ cos 120°? Trigonometry. 1 Answer Mr. Hsia May 21, 2018 ...