QUADRATICS-1

Find the maximum value of the quadratic equation:5-6t-8t².

Solution

a=-8, b=-6, c=5

Maximum = 4ac-b²

                        4a

Maximum = (4 x -8 x 5) - (-6)²

                          4(-8)

Maximum = (-160)- 36

                         32

Maximum= -196                         since (-160)- 36=-196

                       32

Maximum = -98 =   -49

                      16         8

Hence maximum value is -49/8

TRY THIS………………………………..

NECTA  2003 QN. 10c

Find the maximum value of the quadratic equation:3+30t-5t².