Question

find the value of k that means 4x² - 3x – k = 0 has no real solutions

Answer 1

So this means we want the discriminant to be less than 0
Do you know what the discriminant is?

Answer 2

yes the discriminant is less than zero and no we dont know the discriminant but because it is minus k i cant work out how the solution will be below zero

Answer 3

Whoops the discriminant is \(b^2-4a*c\)

Answer 4

If you have \[ax^2+bx+c=0 \text{ then the discriminant is } b^2-4ac\]
What swiss said lol

Answer 5

And we want that to be less than 0
\[b^2-4ac<0\]

Answer 6

but if c is a negative how can 9-(4*4*c) make a negative?

Answer 7

c is -k right?

Answer 8

yes

Answer 9

so you have 9-(4*4*(-k))<0

Answer 10

Can you solve this
Do order of operations to the left hand side of the inequality first

Answer 11

as in 16*k<-9 ?

Answer 12

Ok. That is good. :)

Answer 13

Now divide both sides by ____ and you will have what k is

Answer 14

-0.5625 (-9 over 16) ?

Answer 15

Yep but don't forget to include k< in your answer

Answer 16

You did great @leah32568256 :)
Good job.

Answer 17

thank you!