Question

Use the quadratic formula to find any x-intercepts on the graph of the equation.
y=4x^2-2x-5

Answer 1

what are you having trouble with on this?

Answer 2

@HawkCrimson

Answer 3

\[(-b \sqrt[\pm]{b ^{2}-4ac} )/2a\]

Answer 4

where ax^2 +bx + c

Answer 5

okay your first equation was right!

Answer 6

just plug in the values and work it out :)

Answer 7

Trying to do that now =l

Answer 8

so I got, \[2\pm \sqrt{-76} / -4 \] doesnt seem right?

Answer 9

u made a mistake in the square root and the -4

Answer 10

ill show u know

Answer 11

I got it further down to \[-2\pm 2\sqrt{38}/ -4 \]

Answer 12

\[b ^{2}-4ac\]
(-2)^2 - 4(4)(-5)
4 -4(-20)
4+80 = 84

Answer 13

2a
2(4)
8 not -4

Answer 14

\[2\sqrt[\pm]{84}/8\]

Answer 15

understand?

Answer 16

yeah that makes sense, now it's factoring it down.

Answer 17

no, next u square root the 84

Answer 18

so u'll get 9.17

Answer 19

\(84=4\times 21\) so \(\sqrt{84}=\sqrt{4}\sqrt{21}=2\sqrt{21}\)

Answer 20

you get
\[\frac{2\pm2\sqrt{21}}{8}=\frac{2(1\pm\sqrt{21})}{8}=\frac{1\pm\sqrt{21}}{4}\]

Answer 21

umm @satellite73 that is all fun and gud but this question isnt so complicated..

Answer 22

it is if you want to write your answer in simplest radical form
if you want a decimal, then you use a calculator

Answer 23

well thanks i didnt know that :) though we dont need to do that ill keep that in mind thx :D

Answer 24

He did have the correct answer.

Answer 25

Use the quadratic formula to find any x-intercepts on the graph of the equation.
y=4x^2-2x-5

^ That didnt ask for it in the racinal form but ok xD

Answer 26

radical*

Answer 27

that is true, but that's how the instructor had the answer =) no biggie. it wasn't specific enough.

Answer 28

lol ok but on the record, i did most of the work XP