Question

What value of b will cause 16x ^ 2 + bx + 4 = 0 to have one real solution ?

Answer 1

Answer:

b  =  16

Step-by-step explanation:

16*x  + b*x  + 4  =  0

Solving for x we get:

x₁,₂  =   - b  ±  √  b² - 4*a*c   ] / 2*a         (1)

If we take a look to the square root

√ b² - 4*4*16      =  √ b²  - 256

if we make √ b²  - 256    = 0

b²  =  256       ⇒      b  =  16

Then equation (1) becomes:

x₁,₂  = ( - 16  ±  0  ) / 32

x  = -  1/2