Trig

Trig Take an x-axis and an y-axis (orthonormal) and let o be the origin. A circle centered in o and with radius = 1, is called a trigonometric circle or unit circle. Turning counterclockwise is the positive orientation in trigonometry. Angles are measured starting from the x-axis. Two units to measure an angle are degrees and radians An orthogonal angle = 90 degrees = pi/2 radians In this theory we use mainly radians. With each real number t corresponds just one angle, and just one point p on the unit circle, when we start measuring on the x-axis. We call that point the image point of t. Examples: with pi/6 corresponds the angle t and point p on the circle. with -pi/2 corresponds the angle u and point q on the circle. Trigonometric numbers of a real number t With t radians corresponds exactly one point p on the unit circle. The x-coordinate of p is called the cosine of t. We write cos(t). The y-coordinate of p is called the sine of t. We write sin(t). The number sin(t)/cos(t) is called the tangent of t. We write tan(t). The number cos(t)/sin(t) is called the cotangent of t. We write cot(t). The number 1/cos(t) is called the secant of t. point, circle, called, write, number, line, radians, corresponds, angle, unit, one, cos²t, x-axis, tant, sin²t, y-coordinate, x-coordinate, trigonometric, take, real, pi/2, pcostsint, origin, op, just, intersection, exactly, each, distance, degrees, analogous, y1, y-axis, x1, units