+0  
 
0
495
1
avatar+23 

The quadratic equation $2x^2 + bx + 18 = 0$ has a double root. Find all possible values of $b.$

 Jan 26, 2019
 #1
avatar+107405 
+1

2x^2 + bx + 18  =  0

 

If this has a double root......the discriminant will = 0

 

b^2   - 4(2)(18)  = 0

 

b^2 - 144 = 0

 

b^2 = 144            take both roots

 

b = 12    or  b =   -12

 

 

cool cool cool

 Jan 26, 2019

24 Online Users