In graphs of trigonometric functions, it deals with opposites finding the right values. all you need to do is use 360 degrees to calculate the slopes. this would mean that the slope equals point [a] and point with a slope between them, calculated by 'velocity' of the slope coming from the direction the wave is going, to the point the wave is at. you must remember that the 'velocity' is equal to twenty five percent of each value, in that it shares fifty percent between the two 'slopes,' and obviously fifty percent of that is going from one direction, to the neutral direction to the next neutral direction, to the second direction.
But, if you were to observe that in mathematics we use right angles and they can mirror each other, you merely calculate the difference between adding to subtracting from the 'plane,' yes?
I see pie comes up here a lot? well, pie is [22 / 7], so you could say [44 / 7] and half it, yes? this would come down to 6 remainder 2, and half of that is three remainder one. working with remainders is easy, as the answer is [1 / 7] = [14%] of the angle, of course.
But, back to this 'radian stuff.' if a half circle divided by pie is the angle we are looking for, then we need to take 14% = [12% remainder 12] for the correct angle. then, we need to take twelve into fourteen, which leaves us with 15.1 degrees for this radians and how they relate to trigonometric functions.