The curve y=(1-x)(x^2+4x+k) has a stationary point when x=-3, find K help? Watch

Venus fly trap
Badges: 8
Rep:
?
#1
Report Thread starter 5 years ago
#1
Help much appreciated!
0
reply
james22
Badges: 15
Rep:
?
#2
Report 5 years ago
#2
What have you tried?
0
reply
Venus fly trap
Badges: 8
Rep:
?
#3
Report Thread starter 5 years ago
#3
(Original post by james22)
What have you tried?
I just don't know how to go about it...
0
reply
Khallil
Badges: 13
Rep:
?
#4
Report 5 years ago
#4
(Original post by Venus fly trap)
Help much appreciated!
Do you know the properties of a stationary point?
0
reply
krisshP
Badges: 14
Rep:
?
#5
Report 5 years ago
#5
Try using the product rule+the fact that at a stationary point dy/dx=0
0
reply
Venus fly trap
Badges: 8
Rep:
?
#6
Report Thread starter 5 years ago
#6
(Original post by Khallil)
Do you know the properties of a stationary point?
Not really we've just done it very briefly in class, and I'm really not sure about this question!
0
reply
Jonagorn
Badges: 0
Rep:
?
#7
Report 5 years ago
#7
A stationary point is a point on the graph where the derivative of the curve is 0. Therefore, differentiating the expanded equation will give you a quadratic equation which you can then sub in x = -3 to find K.
0
reply
james22
Badges: 15
Rep:
?
#8
Report 5 years ago
#8
(Original post by Venus fly trap)
I just don't know how to go about it...
Stationary points occur when dy/dx=0, so find dy/dx and set it equal to 0. You have been told that x=-3 is a stationary point, so you should get dy/dx=0 when x=-3. Plug in this x value and you should get an equation for k.
0
reply
X

Quick Reply

Attached files
Write a reply...
Reply
new posts
Latest
My Feed

See more of what you like on
The Student Room

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

Personalise

University open days

  • Arts University Bournemouth
    Art and Design Foundation Diploma Further education
    Sat, 25 May '19
  • SOAS University of London
    Postgraduate Open Day Postgraduate
    Wed, 29 May '19
  • University of Exeter
    Undergraduate Open Day - Penryn Campus Undergraduate
    Thu, 30 May '19

How did your AQA GCSE Physics Paper 1 go?

Loved the paper - Feeling positive (202)
30.1%
The paper was reasonable (274)
40.83%
Not feeling great about that exam... (113)
16.84%
It was TERRIBLE (82)
12.22%

Watched Threads

View All