In a right-angled triangle, the cosine function of an angle is the ratio of the length of the adjacent side and the hypotenuse side (of angle θ). In this article, we will discuss the cosine of angle 90 degrees value, which is equal to zero. We will also derive this value using the quadrants of a unit circle. Cos 90 degrees To define the cosine function of an acute angle, consider a right-angled triangle provided with the angle of interest and the sides of a triangle. The three sides of the triangle are defined as follows: In Trigonometry, different types of problems can be solved using trigonometry formulas . These problems may include trigonometric ratios (sin, cos , tan, sec, cosec and cot), Pythagorean identities, product identities, etc. Some formulas including the sign of ratios in different quadrants, involving co-function identities (shifting angles), sum & difference identities, double angle identities, half-angle identities, etc., are also given in brief here. Cosine calculator to easily calculate the cosine function of any number. Calculate cos (x) with our trigonometric calculator. Cos calculator with degrees and radians to express the angle.
