Question

for what value of k does the quadratic equation 4x2-12x-k=0​

Answer 1

Answer:

K < -9

step-by-step explanation:

Given quadratic equation,

4x^2 - 12x - K = 0

According to the general form of a quadratic equation,

ax^2 + bx + c = 0

Here,

a = 4

b = -12

c = -K

Now,

we know that,

In a quadratic equation,

There will be no real roots only when the

Descriminant ( D) < 0

i.e.,

Descriminant is neagative.

A.T.Q

D < 0

=> b^2 - 4ac < 0

Putting the values of a, b and c

we get,

=> (-12)^2 - 4 × (4)×(-K) < 0

=> 144 + 16K < 0

=> 16K < -144

=> K < -144/16

=> K < -9

Hence, for no real roots,

the value ofk=-9

Answer 2

Answer:

Step-by-step explanation:

From the given equation

4x² - 12x - k = 0

a = 4 , b = -12 , c= k

Using b² = 4av

(-12)² = 4×(4)×(c)

144 = 16c

Divide both sides by 16

c = 144/16

c = 9

Full equation: 4x² - 12x - 9 = 0