2a. [1 mark] Write down the first three terms of the binomial expansion of (1 + t) in ascending powers of t. 2b. [4 marks] By using the Maclaurin series for cosx and the result from part (a), show that the Maclaurin 5x4 series for secx up to and including the term in x* is 1 + = + 2 24 2c. [3 marks] By using the Maclaurin series for arctanx and the result from part (b), x arc tan 2x ind lim( X+0 secx-1