Question

Hwlp

Answer 1

@sillybilly123 can you take a look at this when you get a chance

Answer 2

True

Answer 3

there's a pattern in there

try x= 1

1 + 1 - 11 - 9 + 18 = 0

then divide it out

Voca - short of finding a crystal ball or a magic lamp, do you see a way round this?!?!

Answer 4

zarky:

start dividing that by \(x-1\) and see what happens

Answer 5

so divide 1 + 1 - 11 - 9 + 18 = 0 by x-1

Answer 6

divide the original quartic by (x-1) ????

Answer 7

I got \[x^3+2x^2-9x-18\]

Answer 8

\(\huge \checkmark\)

Answer 9

So it would be false?

Answer 10

that's just one root! you gotta solve again

Answer 11

oh okay

Answer 12

so try 1, 2, 3, .... and -1, -2, -3,......

Answer 13

like x-1,x-2,x-3 right?

Answer 14

i don't know what you are learning, so maybe just plotting this is an easy way round it. you know...proving that if \(x >5\) then it just keeps increasing. that requires a certaain kind of knowledge

but maybe you are just learning how to find roots.

so if you could show that \(f(5)>0\) and that \(f'(5) > 0\) you might be sorted.

Answer 15

not a mind reader, but what you say sounds sensible :)

Answer 16

x-2:

Answer 17

x-3

Answer 18

x-(-1)

Answer 19

x-(-2)

Answer 20

x-(-3)

Answer 21

sure

try this:

\((x+3)(x-3)(x+1)(x-1)\)

Answer 22

so divide the equation given by (x+3)(x−3)(x+1)(x−1)

Answer 23

the equation is the product of those terms

Answer 24

but I don't see how that is a reasonable answer to the question asked.

if you could step back and show that \(f(x) >0\) for all \(x > 5\) ..... that's smarter

no idea right now where to start that one though, without jumping upon Calculus. And that is off the menu

Answer 25

but yes, factoring the thing shows ALL the zeroes so you can see that the one furthest along the number line is actually x=3

which proves the point they want you to make.

Answer 26

zarky: you reasonably happy with that ?!?!

Answer 27

so true?

Answer 28

tops

Answer 29

true or false

Answer 30

so @Vocaloid this would be true right, I don't quite understand.

Answer 31

I guess it's true judging by what math has been done so far ;;

Answer 32

Okay thanks, I sometimes don't understand him ^-^