Telephone and electrical lines are allowed to sag between poles so that the tension will not be too great when something hits or sits on the line. Suppose that a line were stretched almost perfectly horizontally betweern two poles that are 30 m apart. If a 0.25-kilogram bird perches on the wire midway between the poles and the wire sags 1.0 cm, what would the tension in the wire be?

The second largest public utility in the nation is the sole provider of electricity in 32 counties of southern florida. to meet the monthly demand for electricity in these counties, which is given by the inverse demand function p = 1,200 – 4q, the utility company has set up two electric generating facilities: q1 kilowatts are produced at facility 1, and q2 kilowatts are produced at facility 2 (so q = q1 + q2). the costs of producing electricity at each facility are given by c1(q1) = 8,000 + 6q12 and c2(q2) = 6,000 + 3q22, respectively. determine the profit-maximizing amounts of electricity to produce at the two facilities, the optimal price, and the utility company’s profit