Answer:
65.56°
Step-by-step explanation:
We know that if we take dot product of two vectors then it is equal to the product of magnitudes of the vectors and cosine of the angle between them
That is let p and q be any two vectors and A be the angle between them
So, p·q=|p|*|q|*cosA
⇒
Given u=-8i-3j and v=-8i+8j


let A be angle before u and v
therefore, 
⇒
Therefore angle between u and v is 65.56°
Answer:
C (-2,1)
Step-by-step explanation:
−2x − y = 3 (1)
−9x − y = 17 (2)
(1) y = -2x - 3
(2) y = -9x - 17
-2x - 3 = -9x - 17
7x = -14
x = -2
y = -2(-2) - 3
y = 4 - 3
y = 1
Answer:
A quadratic equation can be written as:
a*x^2 + b*x + c = 0.
where a, b and c are real numbers.
The solutions of this equation can be found by the equation:

Where the determinant is D = b^2 - 4*a*c.
Now, if D>0
we have the square root of a positive number, which will be equal to a real number.
√D = R
then the solutions are:

Where each sign of R is a different solution for the equation.
If D< 0, we have the square root of a negative number, then we have a complex component:
√D = i*R

We have two complex solutions.
If D = 0
√0 = 0
then:

We have only one real solution (or two equal solutions, depending on how you see it)
178÷2 is 89
Hope this was helpful!
Answer:
30
Step-by-step explanation: