Answer:
The sum of the roots is 0.5
Step-by-step explanation:
<u><em>The correct question is</em></u>
What is the sum of the roots of 20x^2-10x-30
we know that
In a quadratic equation of the form
The sum of the roots is equal to
in this problem we have
so
substitute
<u><em>Verify</em></u>
Find the roots of the quadratic equation
The formula to solve a quadratic equation is equal to
substitute
The roots are x=-1 and x=1.5
The sum of the roots are
----> is ok
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
Answer:
The function is decreasing in the following intervals
A. (0, 1)
C. (2, pi)
Step-by-step explanation:
To answer this question, imagine that you draw lines of slope m parallel to the function shown at each point.
-If the slope of this line parallel to the function is negative for those points then the function is decreasing.
-If the slope of this line parallel to the function is positive for those points then the function is increasing.
Observe in the lines drawn in the attached image. You can see that they have slope less than zero in the following interval:
(0, 1) U (2, pi)
Therefore the correct option is:
A. (0, 1)
C. (2, pi)
