Question

Persamaan kuadrat x^2-p(x-1)=0 memiliki akar kembar, nilai p sama dengan...

A. 2
B. 4
C. 2 akar2
D. 2 akar3
E. 8

Answer 1

Misalkan x^2 - px -p = 0 memiliki akar2 x1 & x2
karena kembar x1=x2
x1+x2 = -(-p)/1
x1+x2 = p
2x1=p
x1 = p/2

x1.x2 = p/1
x1^2=p
(p/2)^2=p
(p^2)/4 = p
p/4 = 1
p = 4