Instruction

1

If you want to find the cosine

cos? = a/c where a is the length of the leg, the length of the hypotenuse.

**of an angle**in a right triangle, you must use the definition of cosine to find the ratio of adjacent leg to the hypotenuse:cos? = a/c where a is the length of the leg, the length of the hypotenuse.

2

If you want to find the cosine

if the angle is acute: cos? = (a2 + b2 – c2)/(2ab);

if the angle is blunt: cos? = (C2 – a2 – b2)/(2ab), where a and b are the lengths of the sides adjacent to the angle, side length opposite corner.

**of angle**in an arbitrary triangle, use the theorem of cosines:if the angle is acute: cos? = (a2 + b2 – c2)/(2ab);

if the angle is blunt: cos? = (C2 – a2 – b2)/(2ab), where a and b are the lengths of the sides adjacent to the angle, side length opposite corner.

3

If you want to find the cosine

**of angle**in an arbitrary geometrical figure, determine the magnitude**of the angle**in degrees or radians, and the cosine**of the angle**to find its value using scientific calculator, tables Bradis or any other mathematical application.Useful advice

Mathematical notation of cosine cos.

The value of a cosine cannot be greater than 1 and less than -1.

The value of a cosine cannot be greater than 1 and less than -1.