ANSWER
D
Step-by-step explanation:
d=√((x_2-x_1)²+(y_2-y_1)²)
Area = side AB * side BC = (5x + 5x + 3)(3x + 92x - 4)
= (10x + 3)(95x - 4) = 950x^2 - 40x + 285x - 12
= 950x^2 + 245x - 12 Answer
This cannot be negative so restriction on x is 950x^2 + 245x > 12
That is x > 0.0421
The cross product of two vectors gives a third vector

that is orthogonal to the first two.

Normalize this vector by dividing it by its norm:

To get another vector orthogonal to the first two, you can just change the sign and use

.