The following hold: {{MATH_246}} {{CMD_247}} From the unit circle we can see {{CMD_248}} {{ENV_249}} {{CMD_250}} via the Pythagorean Theorem that {{MATH_251}} If we divide this expression by {{MATH_252}} we obtain {{MATH_253}} and if we divide {{MATH_254}} by {{MATH_255}} we obtain {{MATH_256}} {{CMD_257}} {{CMD_258}}