Question

the equation whose roots are the roots of x^7+3x^5+x^3-x^2+7x+2=0 with their signs changed is
a.x^7+3x^5+x^3+x^2+7x+2=0
b.x^7+3x^5+x^3+7x-2=0
c.x^7+3x^5+x^3-x^2+7x-2=0

Answer 1

and in b option there is x^2 also after x^3

Answer 2

B....

Answer 3

yes b option

Answer 4

@AllTehMaffs pls..hlp

Answer 5

@Viyang

Answer 6

if you have x to power of n just change the sign of the term x^(n-1) if it exists and change the sign of the integer at the end

Answer 7

then according to that we wud have b option as answer

Answer 8

yes

Answer 9

y...

Answer 10

I think it has to be a - for the last term either both x_0 terms are either positive or negative because it's positive, so if they *both change then that x_0 term *has to stay positive

Right?

Answer 11

i did't get dat how u r getting a and even ans is a

Answer 12

oohh, there are an odd number of roots. nm. My argument doesn't hold. Sorry :/

Answer 13

to get roots with signed changed, just replace 'x' by '-x'

Answer 14

sign of roots changed means -x will satisfy the resulting equation, so thats just f(-x)

Answer 15

what do you get if you put x=-x in
x^7+3x^5+x^3-x^2+7x+2=0

Answer 16

\[ -x^7-3x^5-x^3-x^2-7x+2=0\]

Answer 17

yeah, now you can factor out the -1

Answer 18

x^7+3x^5+x^3+x^2+7x-2=0

Answer 19

doubts ?

Answer 20

no