(1) Min.: , ; max.: , .
(2) .
(4) square inches.
(5) ; ; .
(6) Max. for ; min. for .
(7) Join the middle points of the four sides.
(8) , , no max.
(9) , , .
(10) At the rate of square feet per second.
(11) .
(12) .
(1) Max.: , ; min.: , .
(2) ; ; (a maximum).
(3) (a) One maximum and two minima. (b) One maximum. (; other points unreal.)
(4) Min.: , .
(5) Max: , .
(6) Max.: , . Min.: , .
(7) Max.: , . Min.: , .
(8) , .
(9) .
(10) Speed nautical miles per hour. Time taken hours. Minimum cost £. .