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'.
Fora right angle triangle: cosine angle = adjacent/hypotenuse
To solve for the cosine (COS) of an angle, you can use the unit circle, where the cosine of an angle corresponds to the x-coordinate of the point on the circle at that angle. Alternatively, you can use trigonometric identities or the cosine function on a scientific calculator by inputting the angle in degrees or radians. For specific problem solving, using the cosine rule in triangles may also be applicable to find unknown sides or angles.
60 degrees = 0.5 1/2
cosine = adjacent/hypotenuse
As a decimal: 0.866 As a fraction: √(3)/2
Fora right angle triangle: cosine angle = adjacent/hypotenuse
The cosine function is mathematical equation to determine the adjacent angle of a triangle. The cosine of an angle is the ratio of the length of the hypotenuse: so called because it is the sine of the co-angle.
In a right triangle, the cosine of an angle is defined as the ratio of the adjacent side of that angle to the hypotenuse.
You mean, you have the cosine, and want the angle? That is called arc-cosine, often written as cos-1x. Your scientific calculator should have a "shift" key or something similar, which you press, followed by the cosine key. That will give you the inverse cosine or arc-cosine.
In a right angle triangle it is: cosine ratio = adjacent/hypotenuse
cosine(59 degrees) = 0.51504 (rounded)
Sine of the angle to its cosine.
Sine and the cosine of the angle.
The secant of an angle is the reciprocal of the cosine of the angle. So the secant is not defined whenever the cosine is zero That is, whenever the angle is a multiple of 180 degrees (or pi radians).
at a 45 degree angle, or pi/4
The cosine is ±1/sqrt(5) = ±0.4472 (approx).
Cosine cannot have this kind of high value, it ranges from -1 to +1