maka nilai m = …
Pembahasan:
Syarat grafik parabola dan garis linear saling bersentuhan kalau, D = 0
f(x) = x² – mx + 5 menyinggung garis y = 2x + 1
x² – mx + 5 = 2x + 1
x² + (–m – 2)x + 4 = 0
a = 1; b = (–m–2); c = 4
Syarat saling bersinggungan,
D = 0
b² – 4ac = 0
(–m–2)² – 4.1.4 = 0
m² + 4m + 4 – 16 = 0
m² + 4m – 12 = 0
(m + 6)(m – 2) = 0
m = –6 atau m = 2
m > 0 maka m = 2