As the angle {{MATH_65}} grows larger and larger, the terminal side of that angle spins around the circle. The trigonometric functions of the angle {{MATH_66}} are defined in terms of the terminal side. {{CMD_67}} Suppose {{MATH_68}} is the point at which the terminal side of the angle with measure {{MATH_69}} intersects the unit circle. The the trigonometric functions are defined to be {{MATH_70}} provided these values exist. {{CMD_71}} From the picture, you see that this agrees with what you know about trigonometry for triangles, but it allows us to extend the definition of sine and cosine to all real numbers, instead of only the interval {{MATH_72}} {{CMD_73}}Connections to inverse functions{{CMD_74}}