What are the set of values for x that satisfy the below equation?

MYTUTOR SUBJECT ANSWERS

Answers / Maths / A Level / What are the set of values for x that satisfy the below equation?

504 views

What are the set of values for x that satisfy the below equation?

x² - 9x ≤ 36

1. Draw a graph.

y = x²- 9x and y = 36

2. Find the points of intersection by solving x² - 9x = 36

x² - 9x = 36

x²- 9x - 36 = 0

(x - 12)(x + 4) = 0

Therefore, the lines intersect at x = 12 and x = - 4

3. Either observe from your graph or plug in points either side of the points of intersection.

i) For x < -4

e.g. x = - 5. Sub. into LHS = (-5)²- 9(-5) = 70 > 36

ii) For -4 < x < 12

e.g. x = 0. Sub. into LHS = 0²- 9(0) = 0 < 36

iii) For x > 12

e.g. x = 20. Sub. into LHS = 20² - 9(20) = 400 - 180 = 220 > 36

Therefore, x² - 9x ≤ 36 when -4 ≤ x ≤ 12

Daisy D. A Level Chemistry tutor, GCSE Chemistry tutor, A Level Maths...

10 months ago

Answered by Daisy, an A Level Maths tutor with MyTutor

Still stuck? Get one-to-one help from a personally interviewed subject specialist

330 SUBJECT SPECIALISTS

£24 /hr

Dylan H.

Degree: Materials Science and Engineering (Masters) - Imperial College London University

Subjects offered:Maths, Physics+ 3 more

“I offer tutoring in Maths, Chemistry and Physics and I am confident that I can help students to excel in exams through my engaging and interactive sessions.”

5.0

17 reviews | 24 completed tutorials

Save profile

Mabast H. GCSE Physics tutor, A Level Physics tutor, IB Physics tutor...

View profile

£20 /hr

Mabast H.

Degree: Physics (Bachelors) - Imperial College London University

Subjects offered:Maths, Physics+ 3 more

“Undergraduate Physicist with lots of experience in teaching in different fields and age groups, looking to instil a passion for learning into students.”

MyTutor guarantee

Save profile

Jagan A. 13 Plus Maths tutor, 11 Plus Maths tutor, GCSE Maths tutor,...

View profile

£20 /hr

Jagan A.

Degree: Aeronautics and Astronautics (Masters) - Southampton University

Subjects offered:Maths, Physics

“Engineering, Maths, Physics, Structured Revision, Practice questions, Edexcel, AQA”

5.0

3 reviews | 3 completed tutorials

Save profile

See more A Level Maths tutors

About the author

View profile

£20 /hr

Daisy D.

Degree: Natural Sciences: Chemistry and Mathematics, MSci (Other) - Durham University

Subjects offered:Maths, Physics+ 2 more

“Hi, I'm Daisy! I'm currently in my 3rd year studying an integrated masters course in Natural Sciences (Chemistry and Maths) at Durham University. My main area of interest is the physcial side of both subjects. From a young age, I hav...”

MyTutor guarantee

Save profile

Version:	3.48.0
Build:	c981a57a9cf4
Time:	2017-07-24T15:36:26Z

MYTUTOR SUBJECT ANSWERS

What are the set of values for x that satisfy the below equation?

Still stuck? Get one-to-one help from a personally interviewed subject specialist

330 SUBJECT SPECIALISTS

About the author

You may also like...

Posts by Daisy

Other A Level Maths questions

One-to-one help is at your fingertips