Question

Tentukqn akar2 persamaan kuadrat dgn menggunakan rumus:
1.a)x²-x+12=0
b)4x²+4x+1=0
c)-3x²-5x+2=0

2.dr nmr 1 tentukan akar2 pers X1 dan X2,tentukan nilai dr X1+X2 dan X1.X2!

3.dr nmr 1 tentukan nilai deskriminannya

4.tentukan pers kuadrat yg akar2 berkebalikan degn pers 5x²- 4x-3=0

Answer 1

1. a) ( x-3)( x-4)
    b) (2x +1 )(2x +1)
    c) ( -3x +1)(x + 2)
2. a) x1 = 3, x2=4, X1+ X2 = -b/a =-(-1)/1=1, X2.X2 = c/a = 12/1 = 12
    b) x1 = -1/2, x2 = -1/2, X1 + X2 = -b/a = -4/4=-1, X1.X2 = c/a = 1/4
    c) x1 = 1/3, x2 = -2, X1+X2 = -b/a = -(-5)/-3 = -5/3, X1.X2 = c/a = 2/-3 = -2/3
3 a ) D = b²-4ac = 1-4.1.12=1-48= -47
   b)  D = b²-4ac = 16-4.4.1= 16-16=0
   c) D = b²-4ac = 25- 4.(-3).2 = 25+24=49