We need to find dot products of 2 vectors:
u·v = x1*x2 + y1*y2
u·v = 2*(-6) + 3*4 = -12 + 12 = 0
Another way to write dot product u·v = |u|*|v|*cos α.
Because the do product = 0, we can write
|u|*|v|*cos α = 0.
That means cos α = 0, and thus α=90⁰, so vectors v and u are orthogonal.
Answer:

Step-by-step explanation:
when a line is tangent to a circle, it is perpendicular to the line from the center of the circle to the intersection of the line and the circle. so first we are going to find the slope of the line in the circle.
to find the slope use the formula 
so the slope is -4/3
the slope of the line perpendicular to this is the opposite reciprocal: 3/4 so now we have y= 3/4 x +b, to find b plug in the point (-3,4) to get 4=-9/4 +b, b=25/4 the equation is y=3/4 x +25/4
Answer is •D because of the seburation
-13 is a real number and a rational number.
It's not an interger, because there's no such thing.
But it IS an integer.