step 1
we have the curve

Find out the derivative

step 2
Find out the equation of the line perpendicular to the given curve that passes through the point (0,8)
Remember that
If two lines are perpendicular, then their slopes are negative reciprocal
so
The slope of the perpendicular line is m=-1/2
The equation of the line is given by

where
m=-1/2
point (0,8) ----> y-intercept
substitute

step 3
Find out the intersection of both lines

Equate both equations

Find out the y-coordinate of the point

The coordinates of the point are
