Question 1159403
y = −4x^2 +8x +1
Take the derivative to find a critical point:
dy/dx = -8x + 8 = 0
x = 1
So at the distance of 1 from the end of the board, 
the height is y(1) = -4(1^2)+8+1 = 5
The maximum height is 5m at 1m from end of the board.