3. Determine the maximum or minimum value for y = - 4 (x + 1) 2 + 6 b ) f (x ) = ( x - 5 ) 2 x - s f ( x I 2 - 10 x +2s d) g(x PRACTISING 4. Determine the maximum or minimum valu K methodsq b C a y = x2 - 4x - 1 d) b) f (x ) = x2 - 8x+ 12 e) c) y = 2x2 + 12x f ) 5. Each function is the demand function of of items sold, in thousands. Determine i) the revenue function ii) the maximum revenue in thousand a) p(x) =-x+5 C) b) p(x) = -4x+ 12 d) Iculator to determ7. For each pair of revenue and cost functions, determine i) the profit function ii) the value of x that maximizes profit (find kvertex) R (x ) = - x2 + 24x , C (x ) = 12x + 28 b) R(x) = - 2x2 + 32x, C(x) = 14x + 45 C ) R(x) = - 3x2 + 26x, C(x) = 8x+ 18 d) R(x) = -2x2 + 25x, C(x) = 3x + 17 8. The height of a ball thrown vertically upward from a ro