Compute: {{MATH_181}} {{CMD_182}} The issue here is that {{MATH_183}} might not be in the range of arctangent. To find our missing number, we'll check with a unit circle that we've decorated with the domain of arctangent: {{CMD_184}} {{ENV_185}} {{CMD_186}} Since the points {{MATH_187}} and {{MATH_188}} have the same {{MATH_189}} and {{MATH_190}}-coordinates, {{MATH_191}} {{CMD_192}} {{CMD_193}}