Question

If x + 2 is a factor of x³ – 2ax² + 16, then value of a is

Answer 1

Answer:

a = 2

Step-by-step explanation:

Zero of x+2=0

or, x=-2

p(x)=0 [As x+2 is a factor of p(x)]

p(-2) : 2³ - 2a2² + 16= 0

or, 8 - 2a4 +16=0

or, 8 - 8a -16 =0

or, 8a - 16 = 0

or, 8a = 16

or, a = 16/8= 2

So, 'a' is equal to 2.

Hope it helps :)

Answer 2

Step-by-step explanation:

If x + 2 is a factor of x³ – 2ax² + 16, then value of a is 1.

If (x + 2) is a factor,

x = –2

p(x) = x³ – 2ax² + 16

p(–2) = (–2)³ – 2(a)(–2)² + 16

        0 = –8 – 2(a)(4) + 16

        0 = –8 – 8a + 16

         0 =  –8a + 8

         a = 8/8

         a = 1

Therefore, value of a is 1.