ddxcos
ddxcos is a term that refers to the derivative of the cosine function with respect to its argument. In calculus, the derivative of a function represents the instantaneous rate of change of that function. The cosine function, denoted as cos(x), is a fundamental trigonometric function that describes the ratio of the adjacent side to the hypotenuse in a right-angled triangle, or the x-coordinate of a point on the unit circle.
The derivative of cos(x) with respect to x is -sin(x). This can be derived using the limit