Temperature changes are observed over the course of three summer months and modeled by the function f (x) = 3 cosine (StartFraction pi Over 5 EndFraction x + StartFraction pi Over 5 EndFraction) + 25, where x represents the days after June 1 and f(x) represents the temperature in degrees Celsius on day x. The first occurrence of the highest temperature in the cycle is day with a temperature of °C. The first occurrence of the lowest temperature in the cycle is day with a temperature of °C.