cos(30)cos(55)+sin(30)sin(55)=cos(30-55) = cos(-25)=cos(25) Note: cos(a)=cos(-a) for any angle 'a'. cos(a)cos(b)+sin(a)sin(b)=cos(a-b) for any 'a' and 'b'.
sin(30) = sin(90 - 60) = sin(90)*cos(60) - cos(90)*sin(60) = 1*cos(60) - 0*sin(60) = cos(60).
30 degrees explanation 2Cosx-radical 3=0 Then 2cosx=radical 3 and cos x=(radical 3)/2 Now remember that cos 300 is (radical 3)/2 from the 30/60/90 triangle. So the answer is 30 degrees.
Sin(30) = 1/2 Sin(45) = root(2)/2 Sin(60) = root(3)/2 Cos(30) = root(3)/2 Cos(45) = root(2)/2 Cos(60) = 1/2 Tan(30) = root(3)/3 Tan(45) = 1 Tan(60) = root(3) Csc(30) = 2 Csc(45) = root(2) Csc(60) = 2root(3)/3 Sec(30) = 2root(3)/3 Sec(45) = root(2) Sec(60) = 2 Cot(30) = root(3) Cot(45) = 1 Cot(60) = root(3)/3
Provided that any denominator is non-zero, sin = sqrt(1 - cos^2)tan = sqrt(1 - cos^2)/cos sec = 1/cos cosec = 1/sqrt(1 - cos^2) cot = cos/sqrt(1 - cos^2)
cos(30)cos(55)+sin(30)sin(55)=cos(30-55) = cos(-25)=cos(25) Note: cos(a)=cos(-a) for any angle 'a'. cos(a)cos(b)+sin(a)sin(b)=cos(a-b) for any 'a' and 'b'.
Cos(30) = sqrt(3)/2
0.866
cos(30) is an irrational number and so cannot be expressed as a rational fraction. It is (√3)/2.
sin(30) = sin(90 - 60) = sin(90)*cos(60) - cos(90)*sin(60) = 1*cos(60) - 0*sin(60) = cos(60).
cos 60
Root 3 over 2.
cos(60) = 0.57 x 60 x cos(60) = 7 x 30 = 210
510 ~ (510-360) ~ 150 Cos 510 = Cos 150 = - Cos 30 = - ( radical 3 ) / 2
cos(30 deg) = sqrt(3)/2 = 0.8660 approx.
If tan 3a is equal to sin cos 45 plus sin 30, then the value of a = 0.4.
30 degrees explanation 2Cosx-radical 3=0 Then 2cosx=radical 3 and cos x=(radical 3)/2 Now remember that cos 300 is (radical 3)/2 from the 30/60/90 triangle. So the answer is 30 degrees.