Question

Find the value of k, for which one root of the quadratic equation kx2

-14x+8 = 0 is 2.

Answer 1

Answer:

Step-by-step explanation:

p(x) = kx^2 - 14x +8

p(2) = k(2)^2 - 14(2)+8

      = 4k-28+2

   0 = 4k - 20

     -4k = -20

       k = -20/-4

        k = 5

hope its correct and helps u    

Answer 2

Question:

Find the value of k for which one of the roots of the quadratic equation kx² - 14x + 8 = 0 is 2 .

Answer:

k = 5

Note:

• An equation of degree 2 is know as quadratic equation .

• Roots of an equation is defined as the possible values of the unknown (variable) for which the equation is satisfied.

• The maximum number of roots of an equation will be equal to its degree.

• A quadratic equation has atmost two roots.

• The general form of a quadratic equation is given as , ax² + bx + c = 0 .

• The discriminant of the quadratic equation is given as , D = b² - 4ac .

• If D = 0 , then the quadratic equation would have real and equal roots .

• If D > 0 , then the quadratic equation would have real and distinct roots .

• If D < 0 , then the quadratic equation would have imaginary roots .

Solution:

The given quadratic equation is ;

kx² - 14x + 8 = 0

According to the question,

One of the roots of the given quadratic equation is 2 , thus x = 2 will satisfy the given quadratic equation.

Thus,

=> kx² - 14x + 8 = 0

=> k•2² - 14•2 + 8 = 0

=> 4k - 28 + 8 = 0

=> 4k - 20 = 0

=> 4k = 20

=> k = 20/4

=> k = 5

Hence,

The required value of k is 5 .