FUNCTIONS 7

Find the maximum value of the quadratic equation:5-2t-8t².

Solution

a=-8, b=-2, c=5

Maximum = 4ac-b²

                       4a

Maximum = (4 x -8 x 5) - (-2)²

                          4(-8)

Maximum = (-160)- 4

                         32

Maximum= -164

                      32

Maximum = -41

                      8

Hence maximum value is -41/8

TRY THIS………………………………..

NECTA  2003 QN. 10c

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