MYTUTOR SUBJECT ANSWERS

585 views

How to determine the number of unique real roots of a quadratic equation.

Take any quadratic equation, eg/ 3x2+4x-2=5, and rearrange to equal 0, ie/ 3x2+4x-7=0   (if you have an expression, ie/ there is no equals sign, then simply equate the expression to 0).

Now, we use the discriminant function, b2-4ac, of the quadratic, ax2+bx+c=0. Notice that a=3, b=4, and c=-7, in this case. This means that the discriminant is 42-4*3*(-7)=16-(-84)=100. This is greater than 0. Therefore, there exist 2 unique real roots to our quadratic.

Simply put, if, for any quadratic of the form ax2+bx+c=0, that b2-4ac>0, then there exist 2 unique real roots, if b2-4ac=0 then there is 1 repeated real root, and if b2-4ac<0, then there are no real roots.

Yaniv P. GCSE Maths tutor, GCSE Physics tutor, GCSE Further Mathemati...

2 years ago

Answered by Yaniv, a GCSE Maths tutor with MyTutor


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

462 SUBJECT SPECIALISTS

£24 /hr

Victoria S.

Degree: Physiology (Bachelors) - Liverpool University

Subjects offered:Maths, Biology

Maths
Biology

“Here to help with last minute revision prep! I'm Tory, in my final year studying Physiology at Uni of Liverpool and am a 5* rated tutor here to suit your needs.”

£18 /hr

Benedict C.

Degree: Natural Sciences (Bachelors) - Leeds University

Subjects offered:Maths, Physics

Maths
Physics

“I am studying Physical Natural Sciences at Leeds University. My sessions focus on understanding and making examples work for you.”

MyTutor guarantee

£20 /hr

Josh M.

Degree: Biological Natural Sciences (Bachelors) - Cambridge University

Subjects offered:Maths, Physics+ 3 more

Maths
Physics
Chemistry
Biology
-Oxbridge Preparation-

“Who am I? I'm currently studying Natural Sciences in my third year at Cambridge University, with a focus on Neuroscience. Science is my passion, I've loved it at every level I've studied it, and a desire to pass on my passion is part ...”

About the author

Yaniv P.

Currently unavailable: until 22/12/2015

Degree: Mathematics (Masters) - Bristol University

Subjects offered:Maths, Physics+ 1 more

Maths
Physics
Further Mathematics

“First year Maths undergraduate at the University of Bristol. Looking to tutor Maths and Physics at GCSE and A-Level.”

MyTutor guarantee

You may also like...

Posts by Yaniv

Finding the derivative of a polynomial.

How do you invert a 2x2 matrix?

How do you solve the integral of ln(x)

How to determine the number of unique real roots of a quadratic equation.

Other GCSE Maths questions

How do you solve this problem?

How does Pythagoras Theorem work?

How do I expand brackets by multiplication?

How would I go about drawing a graph if i had no idea how to start?

View GCSE 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