Answer:
Step-by-step explanation:
The formula for the dot product of vectors is
u·v = |u||v|cosθ
where |u| and |v| are the magnitudes (lengths) of the vectors. The formula for that is the same as Pythagorean's Theorem.
which is 
which is 
I am assuming by looking at the above that you can determine where the numbers under the square root signs came from. It's pretty apparent.
We also need the angle, which of course has its own formula.
where uv has ITS own formula:
uv = (14 * 3) + (9 * 6) which is taking the numbers in the i positions in the first set of parenthesis and adding their product to the product of the numbers in the j positions.
uv = 96.
To get the denominator, multiply the lengths of the vectors together. Then take the inverse cosine of the whole mess:
which returns an angle measure of 30.7. Plugging that all into the dot product formula:
gives you a dot product of 96
9514 1404 393
Answer:
see attached
Step-by-step explanation:
The equation can be rewritten to vertex form, so you can tell the vertex is at (2, -5). The leading coefficient of 2 means the points will be twice as far apart vertically than they would be if the leading coefficient were 1. A couple of points are shown in the attached.
y = 2(x^2 -4x) +3
y = 2(x^2 -4x +4) +3 -8 . . . . . . complete the square
y = 2(x -2)^2 -5 . . . . . . . . . . . . finish putting in vertex form
-12 and 18
hope this helps :)