Respuesta :
Answer:
b = ±16
Step-by-step explanation:
Normally to find the number we add to make it a perfect square
We take the coefficient of x
b
Divide by 2
b/2
Then square it
(b/2) ^2
In this case, we are adding 64
(b/2) ^2 = 64
Take the square root of each side
sqrt((b/2) ^2) = sqrt(64)
b/2 = ±8
Multiply each side by 2
b/2*2 = ±8 *2
b = ±16
Answer:
±16
Step-by-step explanation:
What is the square root of 64? 8. But -8 is also a square root of 64. Squaring either 8 or -8 results in ±16.
The following (the square of a binomial) is a "special product" or "perfect square."
(a + b)^2 = a^2 + 2ab + b^2
Compare this pattern to the given: 1 x^2 + bx + 64:
a^2 + 2ab + b^2
Here a = 1 and b^2 = 64. Thus, b must be either +8 or -8.
Then the given expression becomes 1x^2 ± 16x + 64; that is:
b = ±16