Question

If one zero of the quadratic polynomial kx power + 3 X + k then 2 is equal to put the value of k

Answer 1

Step-by-step explanation:

Given -

• One of the zero of polynomial kx² + 3x + k = 0 is 2

To Find -

• Value of k

Now,

p(x) = kx² + 3x + k

Then,

p(2) = k(2)² + 3(2) + k

→ 4k + 6 + k = 0

→ 5k = -6

→ k = -6/5

Hence,

The value of k is -6/5

Verification :-

Substituting the value of k on kx² + 3x + k, we get :

→ -6x²/5 + 3x - 6/5 = 0

→ -6x² + 15x - 6/5 = 0

→ -6x² + 15x - 6 = 0

Now, Factorising this

By using quadratic formula :

• x = -b ± √b² - 4ac

→ -(15) ± √(15)² - 4×-6×-6/2(-6)

→ -15 ± √225 - 144/-12

→ -15 ± √81/-12

→ -15 ± 9/-12

Zeroes are -

x = -15 - 9/-12

→ -24/-12

→ 2

And

x = -15 + 9/-12

→ -6/-12

→ 1/2

Hence,

One of the zero comes is 2 It shows that our answer is absolutely correct.

Answer 2

Answer:

Step-by-step explanation:

One of the zero of polynomial kx² + 3x + k = 0 is 2

To Find -

Value of k

Now,

p(x) = kx² + 3x + k

Then,

p(2) = k(2)² + 3(2) + k

→ 4k + 6 + k = 0

→ 5k = -6

→ k = -6/5

Hence,

The value of k is -6/5

Verification :-

Substituting the value of k on kx² + 3x + k, we get :

→ -6x²/5 + 3x - 6/5 = 0

→ -6x² + 15x - 6/5 = 0

→ -6x² + 15x - 6 = 0

Now, Factorising this

By using quadratic formula :

x = -b ± √b² - 4ac

→ -(15) ± √(15)² - 4×-6×-6/2(-6)

→ -15 ± √225 - 144/-12

→ -15 ± √81/-12

→ -15 ± 9/-12

Zeroes are -

x = -15 - 9/-12

→ -24/-12

→ 2

And

x = -15 + 9/-12

→ -6/-12

→ 1/2

Hence,

One of the zero comes is 2 It shows that our answer is absolutely correct.