MYTUTOR SUBJECT ANSWERS

446 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

255 SUBJECT SPECIALISTS

£20 /hr

Kyna F.

Degree: Materials Engineering (Masters) - Exeter University

Subjects offered: Maths, Science+ 3 more

Maths
Science
Physics
Chemistry
-Personal Statements-

“About me Hello, my name is Kyna and I'm a second year Materials Engineering student studying at theUniveristy of Exeter. I have always had a love for all things science and maths, and would love to help any students in need of extra s...”

£20 /hr

Daniel S.

Degree: MEng Mechanical Engineering (Masters) - Exeter University

Subjects offered: Maths, Further Mathematics

Maths
Further Mathematics

“Hi, I'm Dan and I am currently on the Masters Mechanical Engineering course at Exeter University. I studied Maths, Further Maths and Physics at A-level and recieved A*AA grades for them. I love helping people understand maths and I fi...”

MyTutor guarantee

£20 /hr

Waseem A.

Degree: Physics (Bachelors) - Oxford Alumni University

Subjects offered: Maths, Physics+ 2 more

Maths
Physics
Further Mathematics
.PAT.

“About Me: I studied physics at Oxford University before switching to a mathematics course at Lancaster University and am now aspiring to enrol in a graduate program in mathematics. I have appreciated mathematics and physics from an ea...”

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

Solve the differential equation dy/dx=(y^(1/2))*sin(x/2) to find y in terms of x.

Solve the equation 3^(5x-2)=4^(6-x), and show that the solution can be written in the form log10(a)/log10(b).

How would you differentiate ln(sin(3x))?

Find dy/dx when y = x^2(cos(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