The distance formula is an algebraic expression used to determine the distance between two points with the coordinates (x1, y1) and (x2, y2).
<span><span>D=<span><span>(<span>x2</span>−<span>x1</span><span>)2</span>+(<span>y2</span>−<span>y1</span><span>)2</span></span><span>−−−−−−−−−−−−−−−−−−</span>√</span></span><span>D=<span>(<span>x2</span>−<span>x1</span><span>)2</span>+(<span>y2</span>−<span>y1</span><span>)2</span></span></span></span>
Example
Find the distance between (-1, 1) and (3, 4).
This problem is solved simply by plugging our x- and y-values into the distance formula:
<span><span>D=<span><span>(3−(−1)<span>)2</span>+(4−1<span>)2</span></span><span>−−−−−−−−−−−−−−−−−−</span>√</span>=</span><span>D=<span>(3−(−1)<span>)2</span>+(4−1<span>)2</span></span>=</span></span>
<span><span>=<span><span>16+9</span><span>−−−−−</span>√</span>=<span>25<span>−−</span>√</span>=5</span><span>=<span>16+9</span>=25=5</span></span>
Sometimes you need to find the point that is exactly between two other points. This middle point is called the "midpoint". By definition, a midpoint of a line segment is the point on that line segment that divides the segment in two congruent segments.
If the end points of a line segment is (x1, y1) and (x2, y2) then the midpoint of the line segment has the coordinates:
<span><span>(<span><span><span>x1</span>+<span>x2</span></span>2</span>,<span><span><span>y1</span>+<span>y2</span></span>2</span>)</span><span><span>(<span><span><span>x1</span>+<span>x2</span></span>2</span>,<span><span><span>y1</span>+<span>y2</span></span>2</span>)</span><span>
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I agree with you on this problem. It is A. If that is the final answer, the negative exponent must be flipped in order to be positive. According to the equation, it is not positive so it is not a simpflied polynomial.

The probability of getting 0 heads in 4 tosses (or equivalently, 4 tails) is

.
So the desired probability is
7 is the answer. hope this helps!