How do you find the distance between two complex numbers?
For two points in the complex plane, the distance between the points is the modulus of the difference of the two complex numbers. (s − a)+(t − b)i = (s − a)2 + (t − b)2. So, d = (s − a)2 + (t − b)2 is the difference between the two points in the complex plane.
Answer:

Step-by-step explanation:
a reciprocal is a number that when multiplied by a given number gives 1 as product.
16 * x = 1
x = 1/16
9/10 * x = 1
x = 10/9
Answer:
Anna's walk as a vector representation is
and refer attachment.
Step-by-step explanation:
Let the origin be the point 1 from where Ann start walking.
Ann walks 80 meters on a straight line 33° north of the east starting at point 1 as shown in figure below,
Resolving into the vectors, the vertical component will be 80Sin33° and Horizontal component will be 80Cos33° as shown in figure (2)
Ann walk as a vector representation is 
Thus, Anna's walk as a vector representation is 
In short, for a vertical parabola, namely one whose independent variable is on the x-axis, usually is x², if the leading term coefficient is negative, the parabola opens downward, and its peak or vertex is at a maximum, check the picture below at the left-hand-side.
and when the leading term coefficient is positive, the parabola opens upwards, with a minimum, check the picture below at the right-hand-side.