Question 616971
  <pre><font face = "Tohoma" size = 3 color = "indigo"><b> 
Hi, 
where the function is increasing and where it is decreasing.
f(x) = -x^2 - 8x
Taking the 1st derivative:
 f'(x) =  -2x - 8   
 f'(x) > 0 when x < -4  and  f'(x)< 0 when x > -4
function is increasing when x < -4 and  is decreasing when x >-4

 {{{drawing(300,300,   -20,20,-20,20, grid(1),

graph( 300, 300, -20,20,-20,20,0,-x^2-8x))}}}