The easiest way to solve this problem is by using the Pythagorean theorem :D
Pythagorean theorem: [-b +- sqrt(b^2 - 4ac)]/2a
5 = a
-1 = b
6 = c
therefore, by plugging these values in!
[-(-1) +- sqrt((-1)^2 - 4(5)(6))]/2(5)
[1 +- sqrt(1 - 120)]/10
Oh so we're using imaginary numbers, so in this case you'll need to know that i = sqrt(-1), so keep this in mind (I can see why this was so difficult)
[1 +- sqrt(119)*i]10
answers:
( 1 + i*sqrt(119) ) / 10
( 1 - i*sqrt(119) ) / 10
The x values are the same for both green dots, so you are looking at a simplified version of the distance formula.
d = sqrt( (x2 - x1)^2 + (y2 - y1)^2 )
Since x1 = x2 = 5, the first set of brackets = (5 - 5) = 0
d = sqrt( y2 - y1)^2 )
d = y2 - y1
y2 = 5
y1 = - 1
d = 5 - - 1
d = 6 Answer
The answer to this question is going to be letter B
Domain of f = R .............