garis y=6x memotong parabola y=x^2+a tepat disatu titik maka nilai a

y1 = y2
x²+a = 6x
x²-6x+a = 0

Tepat 1 titk D = 0
D = b²-4ac
0 = (-6)²-4.1.a
= 36-4a
4a = 36
a = 9