Suppose we have functions {{MATH_67}} and {{MATH_68}} with: {{ENV_69}} Find the formula for {{MATH_70}} and state its domain. {{CMD_71}} While the domain of {{MATH_72}} is {{MATH_73}}, its range is only {{MATH_74}}. This is exactly the domain of {{MATH_75}}. That means for any {{MATH_76}} in {{MATH_77}}, the value of {{MATH_78}} is in {{MATH_79}} which means it lies in the domain of {{MATH_80}}. This means that the domain of {{MATH_81}} is {{MATH_82}}. {{COMMENT_83}} Now we may substitute {{MATH_84}} for each instance of {{MATH_85}} found in {{MATH_86}} and so {{ENV_87}} {{CMD_88}} {{CMD_89}}