Question

Find value of a and b so that x^2-4 is a factor of ax^4+2x^3-3x^2+bx-4

Answer 1

Answer:

a=1 b=-8

Step-by-step explanation:

x^2-4=0

x^2=4

x=2

p (x)=ax^4+5x^3+3x^2-bx-4

=a(2)^4+5(2)^3+3(2)^2-b(2)-4

=16a+16-12+2b-4

=16a+4+2b-4

=16a+2b=0

=2 (8a+b)=0

p(-2)=16a-16-12-2b-4=0

=16a-2b-32=0

=16a-2b=32

16a+2b=0

16a-2b=32

- + -

4b=-32

b=-32/4

b=-8

put this in 1

16a-16=0

16a=16

a=1