JAMB - Mathematics (1978 - No. 18)
The minimum point on the curve y = x2 - 6x + 5 is at
(1, 5)
(2, 3)
(-3, -4)
(3, -4)
解释
Given the curve \(y = x^{2} - 6x + 5\)
At minimum or maximum point, \(\frac{\mathrm d y}{\mathrm d x} = 0\)
\(\frac{\mathrm d y}{\mathrm d x} = 2x - 6\)
\(2x - 6 = 0 \implies x = 3\)
Since 3 > 0, it is a minimum point.
When x = 3, \(y = 3^{2} - 6(3) + 5 = -4\)
Hence, the turning point has coordinates (3, -4).