Question

If x + 2 is a factor of x^3 - 2ax^2 +16, then value of a is i) 3 ii) 1 iii) 4

Answer 1

Answer:

ii) 1

Step-by-step explanation:

Let p(x) = $x^3-2ax^2+16$

Given that x+2 = 0

Then => x = -2

Putting this in p(x)

p(-2) = $(-2)^3-2a(-2)^2+16$

By remainder theorem , Remainder will be zero

0 = -8-8a+16

0 = -8a+8

-8a = -8

Dividing both sides by -8

=> a = 1

Answer 2

Answer:

a=1 is the answer

Step-by-step explanation:

let

p(x)=x³-2ax²+16

put x= -2

p(-2)=(-2)³-2a(-2)²+16

p(-2)=-8+16-8a

p(-2)=8-8a

as (x+2) is a factor of p(x) then p(x) is equal to zero

8-8a=0

8=8a

a=1

i hope this will help you