MYTUTOR SUBJECT ANSWERS

652 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

306 SUBJECT SPECIALISTS

£20 /hr

Bukky O.

Degree: Maths with Finance (Bachelors) - Exeter University

Subjects offered:Maths, Chemistry

Maths
Chemistry

“Hi, I'm Bukky (pronounced book-ee) and my aim is to not only help your child excel in Maths but also hopefully enjoy it too”

£20 /hr

Giorgos A.

Degree: Mechanical Engineering with Renewable Energy (Masters) - Edinburgh University

Subjects offered:Maths, Physics

Maths
Physics

“Feel rewarded helping younger students. Nobody is born knowing everything, life is a learning process and my aim is to help you achieve your goals.”

MyTutor guarantee

£22 /hr

Lewis C.

Degree: Natural Sciences (Masters) - Durham University

Subjects offered:Maths, Physics+ 1 more

Maths
Physics
Further Mathematics

“I aim to create an interesting and productive atmosphere in my tutorials where the tutee can enjoy engaging with the subject. ”

About the author

Nicholas B. GCSE Maths tutor, A Level Maths tutor

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

Integrate 8x^3+4 with respect to x.

Express (√5+4)/(√5-2) in the form p+q√5 where p and q are integers.

A stone, of mass m , falls vertically downwards under gravity through still water. The initial speed of the stone is u . Find an expression for v at time t .

How do I evaluate composite functions?

View A Level Maths tutors

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

mtw:mercury1:status:ok