Question

Use the quadratic formula to find the x-intercepts of the function. Round to the nearest tenth, if necessary.
y = 2x2 + 7x + 5

Answer 1

@timo86m

Answer 2

Do you know the quadratic formula?

Answer 3

x intercepts is just another word for zero or roots
make y=0
y = 2x2 + 7x + 5

0 = 2x2 + 7x + 5

Answer 4

nope

Answer 5

do you know what a y-intercept is?

Answer 6

0 = (2)x2 + (7)x + (5)
a b c
2 7 5
http://www.purplemath.com/modules/quadform.htm plug thos numbers in the formula

Answer 7

X intercepts not y @jdoe0001

Answer 8

hmm, pretty sure I read it correctly earlier on, yes, it does say NOW x-intercept

Answer 9

http://www.purplemath.com/modules/quads/qform01.gif

Answer 10

@jdoe0001 when I clicked on tim's link all it showed was a logo will you help me walk though it

Answer 11

\(\bf \text{quadratic formula}\qquad \qquad
x= \cfrac{ - b \pm \sqrt { b^2 -4ac}}{2a}\\
\begin{matrix}
&a& b & c\\
y = &2x^2 &+ 7x& + 5
\end{matrix}\\
\qquad \qquad \qquad \qquad \qquad \qquad x= \cfrac{ - (7) \pm \sqrt { (7)^2 -4(2)(5)}}{2(2)}\)

Answer 12

okay....

Answer 13

so the root will give you 2 values for "x", those 2 are the solution or so-called zeros

Answer 14

okay I think im still with you

Answer 15

so, what did you get? :)

Answer 16

just a sec and ill tell you:)

Answer 17

ok

Answer 18

I got 27

Answer 19

27?

Answer 20

from \(x= \cfrac{ - (7) \pm \sqrt { (7)^2 -4(2)(5)}}{2(2)} \ \ ?\) hardly

Answer 21

yea I put two in the places of x

Answer 22

hmm actually you're meant to simplify only the right-hand side

Answer 23

Oooo

Answer 24

\notice the \(\huge \pm \)

Answer 25

it means 2 solutions, one using the +, another using the -