loitzl9006:
a)
2x
2+6x+4=0
a=2, b=6, c=4
Δ=b
2−4ac=6
2−4*2*4=36−32=4
√Δ=2
| −b−√Δ | | −6−2 | | −8 | |
x1= |
| = |
| = |
| =−2 |
| 2a | | 2*2 | | 4 | |
| −b+√Δ | | −6+2 | | −4 | |
x2= |
| = |
| = |
| =−1 |
| 2a | | 2*2 | | 4 | |
b)
x
3+2x
2−3x=0
x(x
2+2x−3)=0
x=0 lub x
2+2x−3=0
x
2+2x−3=0
a=1, b=2, c=−3
Δ=b
2−4ac=2
2−4*1*(−3)=4+12=16
√Δ=4
| −b−√Δ | | −2−4 | | −6 | |
x1= |
| = |
| = |
| =−3 |
| 2a | | 2*1 | | 2 | |
| −b+√Δ | | −2+4 | | 2 | |
x2= |
| = |
| = |
| =1 |
| 2a | | 2*1 | | 2 | |
odp. do b):
x
1=−3, x
2=1, x
3=0