quadratic equation?

Question

how do I find the roots of x^-4x-1=0 ussing the quadratic formula?

Answer 1

I'll assume you meant x^2 - 4x - 1 = 0

The quadratic formula says that if

ax^2 + bx + c = 0

then

x = ( -b +/- sqrt (b^2 - 4 a c) ) / 2a

In your problem,

a = 1
b = -4
c = -1

Plug 'em in and both add and subtract the square root to get your answer.

Answer 2

I presume you mean x^2 - 4x - 1 = 0.

Just plug it in. In this case, a = 1, b = -4, and c = -1. So:

x = (-b +/- sqrt(b&2 - 4ac))/2a

= (4 +/- sqrt(16 + 4))/2 = (4 +/- 2 sqrt(5))/2

So the roots are 2 + sqrt(5) and 2 - sqrt(5)

Answer 3

x=(-b±√(b^2-4ac))/2a <----- ok thats the quadratic equation!! x which equals 1 is (a), -4 is (b), and -1 is (c). So you just plug it in and then add and subtract to get your two answers!! If you add you should get 4.25 and if you subtract you get -0.25. So I'm sure you'll you add because you don't want a negative number!!