Answer:
False
Step-by-step explanation:
the <u>dot product</u> between two vectors A and B is:
A·B=AB
where
is the angle between the vectors, if they are parallel, this angle is zero. so
and so the dot product is:
A·B =AB
and since 
the dot product is equal to
A·B=AB
The dot product of parallel vectors is NOT zero
We know that
In any quadrilateral where the vertices are on the circumference of a circle, the opposite angles add up to

degrees.
So,
in this problem

therefore
the answer is
ANSWER

EXPLANATION
The equation of the circle with radius r and centre (a,b) is given by

The radius is

We need to determine the center of the circle from the given equation of another circle, which is,

We complete the square to obtain,





The centre of this circle is (4,3)
Hence the center of the circle whose equation we want to find is also (4,3).
With this center and radius 2, the required equation is,

Therefore the correct answer is C.
<u>We'll assume the quadratic equation has real coefficients</u>
Answer:
<em>The other solution is x=1-8</em><em>i</em><em>.</em>
Step-by-step explanation:
<u>The Complex Conjugate Root Theorem</u>
if P(x) is a polynomial in x with <em>real coefficients</em>, and a + bi is a root of P(x) with a and b real numbers, then its complex conjugate a − bi is also a root of P(x).
The question does not specify if the quadratic equation has real coefficients, but we will assume that.
Given x=1+8i is one solution of the equation, the complex conjugate root theorem guarantees that the other solution must be x=1-8i.