# C1 urgent helpWatch

Announcements
#1
Hi,

I have a question:

using the discriminant show that the equation x^2-4x+5=0 has no real roots

i used b^2-4ac but i can't show it has no real roots

Thank you
0
5 years ago
#2
(Original post by M.M.HUSSAIN)
Hi,

I have a question:

using the discriminant show that the equation x^2-4x+5=0 has no real roots

i used b^2-4ac but i can't show it has no real roots

Thank you
What did you get when you used b^2-4ac
0
5 years ago
#3
4^2-4x(1)(5)=16-20=-4 therefore no real roots. You just have to show that the number is negative.
1
#4
(Original post by techno-thriller)
4^2-4x(1)(5)=16-20=-4 therefore no real roots. You just have to show that the number is negative.
oh right thanks
0
5 years ago
#5
(Original post by M.M.HUSSAIN)
oh right thanks
Do you understand why that works

After all, I assume that you got -4 but could not finish the question
0
X

new posts
Latest
My Feed

### Oops, nobody has postedin the last few hours.

Why not re-start the conversation?

see more

### See more of what you like onThe Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

### University open days

• London Metropolitan University
Tue, 21 May '19
• Brunel University London
Wed, 22 May '19
• University of Roehampton
Wed, 22 May '19

### Poll

Join the discussion

#### How did your AQA A-level Economics Paper 1 go?

Loved the paper - Feeling positive (53)
14.17%
The paper was reasonable (189)
50.53%
Not feeling great about that exam... (91)
24.33%
It was TERRIBLE (41)
10.96%