tolong banget yaa yang nomor 57 cuma 1 soal kok

x1 + x2 = -b/a = -p/1 = -p
x1.x2 = c/a = p/1 = p
x1² + x2² = (x1+x2)² - 2x1.x2

x1² + x2² - 2x1.x2 = (x1 + x2)² - 2x1.x2 - 2x1.x2
= (x1+x2)² - 4x1.x2
= (-p)² - 4(p)
= p² - 4p
nilai minimum turunan = 0
2p - 4 = 0
2p = 4
p = 2