Question

If (x-2) is a factor of x²-ax+4, then the value of 'a' is​

Answer 1

Answer:-

Let,

p(x) = x² - ax + 4

Factor of p(x) = (x - 2) [Let it be = g(x)]

Zero of g(x) :-

x - 2 = 0

→ x = 2

As per the remainder theorem, if we put the value of zero of the factor to the multiple of the factor, we will get 0.

∴ p(2) = (2)² - a(2) + 4

= 4 - 2a + 4

= 8 - 2a

So, the value of p(2) would be zero because we have put the zero of it's factor.

Or, 8 - 2a = 0

Or, - 2a = - 8

Or, a = 8/2

Or, a = 4

∴ Value of (a) in p(x) is (4).

Or,

p(x) = x² - 4x + 4.

Answer 2

p(x) = x - 2

→ x - 2 = 0

→ x = 0 + 2

.°. x = 2

______________....

g(x) = x²- ax + 4 = 0

→ Putting the value of x

→ (2)²- a(2) + 4 = 0

→ 4 - 2a + 4 = 0

→ 8 - 2a = 0

→ -2a = 0 - 8

→ -2a = -8

" - " are cancel in both sides..

→ a = 8 ÷ 2

.°. a = 4

So,the value of a is 4...