I need help with this question.

The prices of inputs ($1; 12; Is; IA) are (4; 1; 3; 2). (1) If the production function is given by f(x1, x2) = min(x1,12}, what is the minimum cost of producing one unit of output? (2) If the production function is given by f ($3, r) = 13 + 14, what is the minimum cost of producing one unit of output? (3) If the production function is given by f($1, $2, Is, I.) = min(* + 12, Is + IA), what is the minimum cost of producing one unit of output? (4) If the production function is given by f ($1, 12, Is, I.) = min(1, I2}min{Is, IA}, what is the minimum cost of producing one unit of output