Question

Plz.. I need ur help

For what values of k does the quadratic equation 4x2 -12x -k =0 have no real roots??

Answer 1

hello friend

b²-4ac

put the value

144-4(4)(k)

144+16k

16k=-144

k=-144/16

k=-9

Answer 2

Answer:

The given quadratic equation have no real roots if k is less than -9.

Step-by-step explanation:

The given quadratic equation is

$4x^2-12x-k=0$

A quadratic equation $ax^2+bx+c=0$ have no real roots if its discriminant is less than 0.

$b^2-4ac<0$

$(-12)^2-4(4)(-k)<0$

$144+16k<0$

$16k<-144$

$k<\frac{-144}{16}$

$k<-9$

Therefore, the given quadratic equation have no real roots if k is less than -9.