Question

For what value of b will the polynomial p(x)= -2x^3+bx^2-5x+2 have the same remainder when it is divided by x-2 and x+1

Answer 1

to get the remainder when p(x) is divided by x-2, just find p(2)
know how to ?

similarly,
to get the remainder when p(x) is divided by x+1, just find p(-1)

and since they are equal, you equate p(2) = p(-1)

got this ?

Answer 2

oh omg okay ill try this

Answer 3

I got 5, but the answr is 11

Answer 4

The Remainder Theorem:

When you divide a polynomial f(x) by x-c the remainder r will be f(c)

Answer 5

ok let me try

Answer 6

Okay

Answer 7

when x=-1, p(-1) = b+9

Answer 8

when x=2, p(2) = 4b-24

Answer 9

so, 4b-24 = b+9
3b = 9+24
b=33/3

Answer 10

where did you made an error ?

Answer 11

I somehow got 3b=-9+24

Answer 12

Maybe mis calculated. but I understand how you did it. Thank you so much

Answer 13

so your when x=-1, p(-1) = b-9 instead of b+9 ?

Answer 14

Actually -b+9. I have to re-do that part, I think I messed up by accident somewhere

Answer 15

Ah. b(-1)^2 should have been positive b but I wrote negative by mistake

Answer 16

ok ok, glad that you got it :)
welcome ^_^

Answer 17

:)