MYTUTOR SUBJECT ANSWERS

365 views

The quadratic equation 2x^2 + 8x + 1 = 0 has roots x1 and x2. Write down the value of x1+x2 and x1*x2 and find the value of x1^2 + x2^2

If a quadratic equation is of the form : ax^2 +bx +c =0

and has roots x1 and x2, then the following statements are true:

x1+x2 = - b/a

x1*x2 =  c/a

In our case: x1+x2 = - 8/2 = -4

and x1*x2 = 1/2

Now, x1^2 + x2^2 = (x1+x2)^2 -2*x1*x2

= (-4)^2  -2 * 1/2 = 16 - 1 = 15

Bogdan-Adrian M. A Level Maths tutor

1 year ago

Answered by Bogdan-Adrian, an A Level Maths tutor with MyTutor


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

244 SUBJECT SPECIALISTS

£24 /hr

Barnaby W.

Degree: Mathematics (Masters) - Southampton University

Subjects offered: Maths, Further Mathematics

Maths
Further Mathematics

“ I have always enjoyed tutoring. I find that it gives me real satisfaction to see a child or student you have helped feel much more confident”

£20 /hr

Visitation L.

Degree: Biomedical sciences (Bachelors) - Durham University

Subjects offered: Maths, Biology

Maths
Biology

“Hi, I am Visitation, a second year Biomedical scientist at Durham. Science and Maths are such fascinating subjects and I would like to share my passion and help you through my tutorials!”

£20 /hr

Dylan D.

Degree: Mathematics MMath (Masters) - Bath University

Subjects offered: Maths

Maths

“About me I'm studying Maths at the University of Bath. I really enjoy the subject, and genuinely love learning and talking about Maths- which often surprises some who don't appreciate it so much! -But if I can help inspire others to e...”

About the author

Bogdan-Adrian M.

Currently unavailable: for regular students

Degree: Mathematics and Computer Science (Masters) - Bristol University

Subjects offered: Maths

Maths

“I am an undergraduate, Mathematics and Computer Science student at the University of Bristol. In 2014 I graduated from "Petru Rares" National College passing my Baccalaureate exam with 10/10 in Mathematics. I participated in numerous ...”

MyTutor guarantee

You may also like...

Posts by Bogdan-Adrian

Given that (cos(x)^2 + 4 sin(x)^2)/(1-sin(x)^2) = 7, show that tan(x)^2 = 3/2

If y = 1/(x^2) + 4x, find dy/dx

The quadratic equation 2x^2 + 8x + 1 = 0 has roots x1 and x2. Write down the value of x1+x2 and x1*x2 and find the value of x1^2 + x2^2

Other A Level Maths questions

Intergrate ln(x) with resepct to x

How to calculate the inverse of a 2x2 matrix

What is an integral?

How can I find the area under the graph of y = f(x) between x = a and x = b?

View A Level Maths tutors

Cookies:

We use cookies to improve our service. By continuing to use this website, we'll assume that you're OK with this. Dismiss

mtw:mercury1:status:ok