Let the demand and supply functions for a commodity be qd = d(p, yo) (dp < 0; dyo > 0) qs = s(p, t.) (sp > 0; st. < 0) where yo is income, to is the tax on the commodity, and both are exogenous. (a) impose the equilibrium condition (qd = qs) to express the market equilibrium in a single general function f. (b) check whether the sufficient condition to apply the implicit-function theorem is satisfied. (c) find @p*/@yo, and @p*/@to. sign each of them, and explain what the sign on each of them implies economically. (d) given the fact that in equilibrium qs = qd = q*, use the chain rule to find aq* /ay, and əq* /at.. sign each of them, and explain the economic implications of each of them.