ok thanks (1 Viewer)

muttiah

Banned
Joined
Aug 18, 2006
Messages
138
Gender
Male
HSC
2007
When a polynomial is divided by (2x+1)(x-3) the remainder is 3x -1 . What is the remainder when the polynomial is divided by 2x+1

p(x)= (2x+1)(x-3).Q(x) + (3x-1)

p(-1/2) = 3(-1/2) -1

this doesnt equal 1/2.. but the book has it has 1/2.. they took P(1/2). how come?
 

haque

Member
Joined
Sep 2, 2006
Messages
426
Gender
Male
HSC
2006
either the book is wrong or u copied down the q wrong-but the book's probably wrong-if ur method's correct then don't panic if the book's answer doesn't match
 

Slidey

But pieces of what?
Joined
Jun 12, 2004
Messages
6,600
Gender
Male
HSC
2005
muttiah said:
When a polynomial is divided by (2x+1)(x-3) the remainder is 3x -1 . What is the remainder when the polynomial is divided by 2x+1

p(x)= (2x+1)(x-3).Q(x) + (3x-1)

p(-1/2) = 3(-1/2) -1

this doesnt equal 1/2.. but the book has it has 1/2.. they took P(1/2). how come?
Have faith in yourself. The reason you used x=-1/2 is because 2x+1=0 produces that. Oh, and they didn't use P(1/2), since you don't know what the quotient, Q(x), is and x=1/2 wouldn't multiply Q(x) to zero. =)

That is to say, you can only know what the remainder is when P(x) is divided by either a(2x+1) or b(x-3), where a and b are arbitrary scalars.
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top