MYTUTOR SUBJECT ANSWERS

281 views

What are the roots of 3x^2 + 13x + 4 ?

To find the roots, we solve the equation 3x2 + 13x + 4 = 0.

We could try factorising the equation, which gives us

(3x + 1)(x + 4) = 0

So the roots are x = -1/3 and x = -4.

Alternatively, we could use the quadratic formula;

x = (-b +/- sqrt( b2 - 4ac)) / 2a

[note that sqrt(x) is the square root of x]

So here;

x= (-13 +/- sqrt(132 - 4*3*4)) / 2*3

   = (-13 +/- sqrt(169 - 48)) / 6

   = (-13 +/- sqrt(121)) / 6

   = (-13 +/- 11) / 6

   = (-13 + 11) / 6     or     (-13 - 11) / 6

   = -2 / 6      or      -24 / 6

   = -1 / 3      or      -4

So again, the roots are x = -1 / 3 or x = -4.

Nicholas B. GCSE Maths tutor, A Level Maths tutor

2 years ago

Answered by Nicholas, an A Level Maths tutor with MyTutor

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

182 SUBJECT SPECIALISTS

£20 /hr

Mrinank S.

Degree: Engineering (Masters) - Cambridge University

Subjects offered: Maths, Physics+ 4 more

Maths
Physics
Further Mathematics
Economics
Chemistry
-Oxbridge Preparation-

“Hey there! I'm a second year undergraduate student at the University of Cambridge, studying Engineering. I am really passionate about using science and maths to make the world around us a better place.  I am a patient and friendly tu...”

£20 /hr

Tom V.

Degree: Mechanical Engineering (Masters) - Leeds University

Subjects offered: Maths, Physics

Maths
Physics

“About MeHello! I'm Tom, I'm in my first year studying mechanical engineering at the University of Leeds. I've always loved sicence, being particularly drawn to physics and maths from a young age. I loved the methodical, logical appro...”

MyTutor guarantee

£20 /hr

Oscar Z.

Degree: General Engineering (Bachelors) - Durham University

Subjects offered: Maths, Physics+ 1 more

Maths
Physics
Further Mathematics

“I am a second year General Engineering student at Durham University. I have a passion for science and technology and often find delight in finding out how things work. Richard Feynman (Nobel Laureate) puts it better! https://www.youtu...”

About the author

Nicholas B.

Currently unavailable: for new students

Degree: Mathematics with Study in Continental Europe (Masters) - Bristol University

Subjects offered: Maths

Maths

“I'm in my first year studying maths at Bristol. I'm enthusiastic about my subject and interested in helping others with their learning.”

MyTutor guarantee

You may also like...

Other A Level Maths questions

What is a stationary point and how do I find where they occur and distinguish between them?

Differentiate x^2+6x+1

How does the product rule for differentiation work

Differentiate y = (6x-13)^3 with respect to x

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