Need help with the first part (1)

Question

Need help with the first part (1).

Consider the following production function:
f (21, $2) =2142
1-a
1. Solve the cost minimization problem of the firm.
2. Show that for a = 0.5 the cost function of the firm is given by c(y) = 2 (w1w2)
y.
Microeconomics