Question

Persaamaan 2x² - 2mx + (2m-3)= 0 memiliki akar kembar .nilai m adalah....................
jawab dgn detail

Answer 1

Akar kembar
D = 0
maka
(-2m)² - 4.4(2m - 3) = 0
4m² - 32m + 48 = 0
bagi 4 kedua ruas
m² - 8m + 12 = 0
(m - 6) (m - 2) = 0
m = 2,6
di pilihan ganda ada 6 sehingga m = 6

Answer 2

A=2 , b= -2m , c=(2m-3)
D = 0
0 = b²-4ac
0 = (-2m)² - 4.2.(2m-3)
0 = 4m² - 16m - 24
0 = m² - 4m - 6
6 = m² - 4m
6 + (4.1/2) = m² - 4m (4.1/2)²
6+ 2 = (m - 2)²
8 = (m -2)²
√8 = m - 2
2 +- √8 =m  , m₁ = 2 + √8  atau  , m₂= 2 - √8