finding the value for m

Question

if the equation below is to have 1 double real root, determine the value for m.

 

1.) mx^2-6x+2=0

Answer 1

In order to have 1 double real root, the discriminant, b²-4ac must equal zero. 

In your problem, a = m, b = -6, and c = 2

b²-4ac = (-6)² -4m(2) = 0

36 - 8m = 0

36 = 8m

9/2 = m

Answer 2

Satisfy the following condition (-6)^2 - 4(m)(2) = 0 ; 36 - 8m = 0 ; 36 = 8m ; m = 4.5 ; x1 = x2 = -(-6)/2(4.5) ;

 

x1 = x2 = 6/9 ; x1 = x2 = 2/3