Find the minimum value of y x2 - 2x - 3 - JAMB Mathematics 2014 Question

y = x² - 2x - 3,

Then (\frac{\delta y}{\delta x} = 2x - 2)

But at minimum point,(\frac{\delta y}{\delta x} = 0),

Which means 2x - 2 = 0

2x = 2

x = 1.

Hence the minimum value of y = x² - 2x - 3 is;

y_min = (1)² - 2(1) - 3

y_min = 1 - 2 - 3

y_min = -4