The average daily high temperature (C)


T(t), left parenthesis, t, right parenthesis, equals, 29, minus, 5, cosine, left parenthesis, start fraction, 2, pi, left parenthesis, t, minus, 12, right parenthesis, divided by, 365, end fraction, right parenthesis.
What are the highest and lowest average daily highs in Karachi? Give exact answers.