a) A firm is a perfectly competitive producer and sells A and good B at RM100 and RM80, respectively.The total cost of producing these goods is given by TC=2Q²_A+2Q_AQ_B+Q_B², where Q_A and Q_B denote the output level of good A and good B, respectively.

I) Find the firm's total profit function

ii)Calculate the value of Q_A and Q_B Which maximise profit.

iii) Using the second order condition (SOC) prove that the profit level is at a maximum