Question

f(x)=4x^2+x-1/4?

Answer 1

i know that answer but i would like to see the steps worked out.

Answer 2

you may need the general quadratic formula

\[x = (-1\pm \sqrt{5})/8\]

Answer 3

are you solving

Answer 4

oh ok, i was trying to solve by completing the square.

Answer 5

thanks!

Answer 6

the quadratic formula is using completing the square, its just a shortcut

Answer 7

rewrite the equation



\[4x^2 + x = 1/4\]

then f

\[\sqrt{4x^2} = 2x\]

then for the middle term \[2(2x \times ?) = x \]

so ? = 1/4

add (1/4)^2 to both sides

\[(2x+1/4)^2 = 5/16\]
\[(2x + 1/4) = +- \sqrt{5/16} = +- \sqrt{5}/4\]

\[2x = (-1\pm \sqrt{5})/4\]

\[x = (-1 \pm \sqrt{5})/8\]

Answer 8

thanks so much!