Problem 3 (20 points). Part I (9 points) Find ALL local and global optimal solutions of the following minimization problems, whose objective function is denoted by f and feasible set by X (do NOT use Matlab or any other solver): (a). f(x) = sin x and X = [0, 3π]; (b). f(x) = sin x and X = [0, 4π]; (c). f(x) = sin x and X = [−π/4,(11/4)π]; (d). f(x) = max(0, x2 − 1) and X = (−[infinity], [infinity]); (e). f(x) = ( 1 x · sin (x), if x 6= 0 0, if x = 0; and X = [0,(2/3)π];

246

step-by-step explanation:

hello from mrbilldoesmath!

answer:   (7x + 6y) ( 49x^2 - 42xy + 36y^2)

discussion:

in general, the factorization of a^3 + b^3 is

a^3 + b^ 3 = (a + b) ( a^2 - ab + b^2)

in our case note that 343 = 7^3 and 216 = 6^3 so the equation becomes:

343x^3 + 216y^3 = (7x)^3 + (6y)^3

if you think of a (above) as 7x and b as 6y the factorization becomes

343x^3 + 216y^3 =

((7x + 6y) (   (7x)^2 - 7x*6y + (6y)^2)   =

(7x + 6y) ( 49x^2 - 42xy + 36y^2)

you,

mrb

(a + b) (a^2 - a b + b^2)

192/15 = 12.8.

12.8

step-by-step explanation:

192/15 is 12.8.

however, it says to round to the nearest foot, which would equal 13.