How do you solve $- 4 x^{2} + x + 1 = 0$ $-4x^2+x+1=0$ using the quadratic formula?

Question

15340 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2014-11-13T17:01:26

$- 4 x^{2} + x + 1 = 0$ $-4x^2+x+1=0$

By comparing with

$a x^{2} + b x + c = 0$ $ax^2+bx+c=0$ ,

we have

${(a=-4),(b=1),(c=1):}$

$x={-b pm sqrt{b^2-4ac}}/{2a}$

$={-1 pm sqrt{1^2-4cdot(-4)cdot1}}/{2cdot(-4)}$

$={-1 pm sqrt{17}}/{-8}={1 pm sqrt{17}}/{8}$

Hence, the solutions are $x={1 pm sqrt{17}}/{8}$ .

I hope that this was helpful.

How do you solve -4x^2+x+1=0−4x2+x+1=0-4x^2+x+1=0 using the quadratic formula?