Question

What are the zeros of the quadratic function f(x) = 8x2 – 16x – 15? x = –1 – and x = –1 + x = –1 – and x = –1 + x = 1 – and x = 1 + x = 1 – and x = 1 +

Answer 1

The zeros of the quadratic function are 2.696 and -0.696.

Explanation:

The given quadratic function is

`f(x)=8x^2-16x-15`

To find the zeros of the function equate the function equal to 0.

`8x^2-16x-15=0`

The quadratic formula is

`x=(-b\pm √(b^2-4ac))/(2a)`

Using the quadratic formula, we get

`x=(-(-16)\pm √((-16)^2-4(8)(-15)))/(2(8))`

`x=(16\pm √(256+480))/(16)`

`x=(16\pm √(736))/(16)`

`x=1\pm (4√(46))/(16)`

`x=1\pm (√(46))/(4)`

`x=1\pm 1.696`

The zeros of the function are

`x=1+1.696=2.696`

`x=1-1.696=-0.696`

Therefore the zeros of the quadratic function are 2.696 and -0.696.

Answer 2

we have that
f(x) = 8x² – 16x – 15

using a graph tool
see the attached figure
x1=-0.696------------> -0.696=(1-1.696)
x2=2.696-------------->2.696=(1+1.696)

the answer is
x1=(1-1.696)
x2=(1+1.696)