fungsi kuadrat f(x)=x²-2px+p+2 berada di sumbu x,maka nilai p yg mungkin

D = 0
b² - 4ac = 0
(-2p)² - 4 (1)(p+2)=0
4p² - 4p -8 =0
2p² -2p -4 = 0
(2p + 1) (p + 4)
2p = -1
p = -1/2 atau p = -4