The x-intercepts are readily identified on the graph: (2,0) and (4,0). The midpoint of a line connecting those 2 points would be (3,0).

has gradient

which at the point (-1, 4, 3) has a value of

I'm not sure what the given direction vector is supposed to be, but my best guess is that it's intended to say
, in which case we have

Then the derivative of
at (-1, 4, 3) in the direction of
is

When you calculate that all up you get 212 <span />
Step-by-step explanation:
Two angles are called suplementary when their measures add to 180 degrees.
D+F= 180
3x+5+2x= 180
5x+5=180
5x= 175
x= 35°
angle D = 3x+5= 3(35)+5= <u>110°</u>