Going out on a limb here and guessing that the function is

Please correct me if this isn't the case.
Recall that

which converges for

.
It follows that

Answer:
x∈{-7√2, 7√2}
Step-by-step explanation:

The line
is already written in the
form. This means that
is the slope. If two lines are perpendicular, their slopes are the anti-inverse of each other, i.e. their product is -1.
So, our perpendicular line has a slope of 
Finally, we want a line passing through (1,1) with slope
:

Answer:
It would be B!
Step-by-step explanation:
D has an obtuse angle, so it can be eliminated.
C has angles that are not vertical, but rather adjacent. Same goes for A!
Hope this helps!
<span>21x+28=14
x= -2/3 or -0.666666666
</span><span>9x+12y=6
x=2/3 or .666666666
y=0</span>