Question

Help! Complex zeros! someone check my answer?

Answer 1

@ryanvarghese12790 it says human calculator next to your name, do you have any idea on this question? hah

Answer 2

give us a sec

Answer 3

No problem. My answer selected in the picture is B but i think it is either b or d

Answer 4

@sammyjpod u can use online calculator to solve this

Answer 5

i plugged it into the online calculator and i couldnt figure out what the definite answer is.

Answer 6

i know that x=-1 and x=3 but im not sure about the third answer

Answer 7

X=-1,x=3,x=3,x=3,x=3,

Answer 8

im confused hahah why so many x=3's?

Answer 9

that is what I got
1st solution = X=-1
Then, the rest (second, third, fourth, fifth) was x=3

Answer 10

so out of my answer choices in this question, is mine correct?

Answer 11

@amistre64 hi! is my answer choice correct for this problem?

Answer 12

got to chk bio chat for a sec ... then i can focus on this

Answer 13

okay..how long do you think it will take?

Answer 14

lol, a minute or so prolly.

Answer 15

haha oh okay thats totally fine

Answer 16

can you type in the equation? ill mess it all up if i try to type it in here ...

Answer 17

$^7-11x^6+48x^5-120x^4+225x^3-243x^2-162x+486$

Answer 18

money signs? you were going for a latex shortcut werrent you $$

Answer 19

oops sorry! i copied it out of the desmos graphing calculator website.

Answer 20

i had already typed it in there.

Answer 21

here is a picture of it graphed.

Answer 22

are you able to help? i have some other things to do so i need to finish this practice soon.

Answer 23

@amistre64

Answer 24

the answer was D. thanks.

Answer 25

x^7 -11x^6 +48x^5 -120x^4 +225x^3 -243x^2 -162x +486
| | | | | |
1 2 3 4 5 6

6,4,2,0 positive rational roots, and complex roots



-x^7 -11x^6 -48x^5 -120x^4 -225x^3 -243x^2 +162x +486
|
1 negative roots


x^7 -11x^6 +48x^5 -120x^4 +225x^3 -243x^2 -162x +486
0 -1 12 -60 180 -405 648 -486
-1| 1 -12 60 -180 405 -648 486 0

so -1 is the only negative root

chk x=3 from whats left over


1 -12 60 -180 405 -648 486
0 3 -27 99 -243 486 -486
3 | 1 -9 33 -81 162 - 162 0
0 3 -18 45 -108 162
3| 1 -6 15 -36 54 0
0 3 -9 18 -54
3 | 1 -3 6 -18 0
0 3 0 18
3| 1 0 6 0

x=3 is 4 times

this leaves us with x^2+6 to play with

Answer 26

um, as is, its either A or C ... not D

Answer 27

x^2 + 6 = 0

x = +- sqrt(-6)