It is a trigonometric function which converts the angle into a ratio.
If the angle A is measured in radians, then
cos(A) = 1 - A^2/2! + A^4/4! - a^6/6! + ...
Cos(2A) = Cos(A + A) Double Angle Indentity Cos(A+A) = Cos(A)Cos(A) - Sin(A)Sin(A) => Cos^(2)[A] - SIn^(2)[A] => Cos^(2)[A] - (1 - Cos^(2)[A] => 2Cos^(2)[A] - 1
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'.
0.766
A Quadrantal angle is an angle that is not in Quadrant I. Consider angle 120. You want to find cos(120) . 120 lies in quadrant II. Also, 120=180-60. So, it is enough to find cos(60) and put the proper sign. cos(60)=1/2. Cosine is negative in quadrant II, Therefore, cos(120) = -1/2.
Cos is the ratio between adjacent side (of the given angle thieta) to the hypotenuse of the triangle.
The cosine function is an even function which means that cos(-x) = cos(x). So, if cos of an angle is positive, then the cos of the negative of that angle is positive and if cos of an angle is negative, then the cos of the negative of that angle is negaitive.
Its a ratio in a right angle triangle, cos angle = adjacent / hypotonuse.
Power factor = cos (angle)PF=cos @
Cos(2A) = Cos(A + A) Double Angle Indentity Cos(A+A) = Cos(A)Cos(A) - Sin(A)Sin(A) => Cos^(2)[A] - SIn^(2)[A] => Cos^(2)[A] - (1 - Cos^(2)[A] => 2Cos^(2)[A] - 1
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(angle) = adjacent / hypotenuse. Cos(a) = a/h Substitute Cos(X) = 5/13 = 0.384615... A = Cos^*-1( 0.384615 .... A = 67.38013505... degrees.
iF the angle of 72 is measured in degrees, cos 72° ≈ 0.3090 If the angle of 72 is measured in radians, cos 72 rad ≈ −0.9673 If the angle of 72 is measured in gradians, cos 72 grad ≈ 0.4258
Well, isn't that just a happy little question! To find the angle for cos equals 0.2874, you can use the arccos function on a calculator. This function will give you the angle in radians where cos of that angle is equal to 0.2874. Just remember to breathe, take your time, and enjoy the process of discovering the beauty of mathematics.
7.66
.385
The answer depends on what "it" is.
If the angle is measured in degrees, then cos(33) = 0.8387, approx.