1. If x degrees is the Celsius temperature, then the number of degrees in the Fahrenheit temperature can be expressed as a function of x. If f is this function, then f(x) degrees is the Fahrenheit temperature and f(x) = 32+ 9/5 x.

Determine the inverse function f^-1 that expresses the number of degrees in the Celsius temperature as a function of the number of degrees in the Fahrenheit temperature. What is the 90°F in °C?​