Find a formula for the described function. an open rectangular box with volume 9 m3 has a square base. express the surface area sa of the box as a function of the length of a side of the base, x. sa = x2+ 36 x m2 state the domain of sa.

Let

x--------> the length side of the square base

h--------> the height of the box

we know that

the volume of the box is equal to

so

the surface area of the box is equal to

(remember that the box is open)

area of the base=

Perimeter of the base=

height=(h) m

substitute

we know that

the value of x can not be negative and the denominator can not be zero

therefore

the answer is

the domain of  SA is x> 0

the domain is the interval-------------> (0,∞)

since the airplane is moving with constant speed then the distance travelled can be calculated by x=u*t

in km/h would be:

x=640*3.5=2.240 km

in m/s would be:

u=640 km/h= 640.000 m/h =640.000/ 3600 m/s =177.8 m/s

t= 3.5 h= 3.5 * 3600 s=12.600 s

then x=u*t= 177.8*12.600= 2.240.280 m