MYTUTOR SUBJECT ANSWERS

525 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

520 SUBJECT SPECIALISTS

£18 /hr

Nidhish J.

Degree: Medicine (Bachelors) - Imperial College London University

Subjects offered:Maths, Physics+ 3 more

Maths
Physics
Chemistry
Biology
.UKCAT.

“Hiya! My name's Nidhish and I am a First Year Medical Student at Imperial College London and am avidly searching for kids with any confusions about their schoolwork to be cleared up! With 2 years worth of tutoring experience from all...”

MyTutor guarantee

PremiumLuke C. A Level Government and Politics tutor, GCSE Government and Po...
£30 /hr

Luke C.

Degree: PPE (Bachelors) - Oxford Alumni University

Subjects offered:Maths, Politics+ 6 more

Maths
Politics
Philosophy and Ethics
Government and Politics
Economics
.TSA. Oxford.
-Personal Statements-
-Oxbridge Preparation-

“I am a Master’s student in Political Science at the University of Chicago, and I’m currently writing a thesis on international security. Last year I graduated from the University of Oxford with a high 2:1 in PPE. In September, I’ll be ...”

£22 /hr

Will W.

Degree: Mathematics (Bachelors) - Durham University

Subjects offered:Maths, Physics+ 2 more

Maths
Physics
Further Mathematics
.STEP.

“Hi, I'm Will. I study Maths and Physics and really enjoy talking about them. I am patient and caring, so will take the time to refine a student’s understanding.”

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

Find the exact value of the gradient of the curve y=e^(2-x)ln(3x-2) at the point on the curve where x=2.

Washing powder is sold in two sizes: Bag 1 is 600 grams for £3.30. Bag 2 is 1500 grams and usually costs £9.60 but currently has 15% off. Which is better value?

When do I use a cosine rule over a sine rule?

How do you solve a simultaneous equation?

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