No,

is not a subspace of

. A simple counter-example to the contrary: let

with

. However, scaling by -1 gives the vector

and

.
Answer:
B
Step-by-step explanation:
I graphed the equation, and the highest point was at 3.7 feet in the air, 4 seconds into the flight. See the graph below. Hope this helps!
Answer:
The second and the third one
Step-by-step explanation:
Area of a rectangle = length (l) * width (w)
A = 30ft * 20ft
A = 600 sq ft
Now the width of a sidewalk that surroundeds it = 3 ft
so now the area of the rectangle with sidewalk= 30+3ft * 20+3ft
A = (33*23) ft
A = 759 sg ft
Area of the sidewalk = 759 - 600
A = 159 sq ft