Question

if the discriminant of the equation kx²-10x+8=9 is 4, then the value of k​

Answer 1

GIVEN :

Discriminant of the equation kx²-10x+8=9 = 4.

To Find :

The value of k

FORMULA USED :

$d = {b}^{2} - 4ac$

where :-

• d = discriminant
• b = second term ( coefficient of x)
• a = first term( coefficient of x²)
• c = constant

Solution :

Now , it is given that discriminant of equation kx²-10x+8=9 is 4.

To find the value of k. We will use the formula :-

$d = {b}^{2} - 4ac$

Now :-

⟹ kx²-10x+8=9

⟹ kx²-10x+8-9 =0

⟹kx²-10x-1=0

In the equation ,kx²-10x-1

• b = -10
• a = k
• c = -1

Now put these values in the formula:-

⟹$d = {b}^{2} - 4ac$

⟹$4= { (- 10)}^{2} - 4(k)( - 1)$

⟹$4= 100 + 4k$

⟹$- 96= 4k$

⟹$k = \frac{ - 96}{4}$

⟹$k = - 24$

ANSWER :

The value of K = -24

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Learn more :-

⟹ For quadratic polynomial of the form ,ax² + bx + c

D = b² – 4ac

Where D = discriminant

⟹For any cubic polynomial of the form ax³ + bx² + cx + d

D= b²c²−4ac³−4b³d−27a²d²+18abcd

Where D = discriminant

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