eMentor live transcript

Live Coaching transcript
Sam eMentor: Is available to chat
Student Tom: hi
Sam eMentor: Hiya, How can I help?
Student Tom: I need some help with Quadratic Equations!

Our Coaches can insert mathematical equations and symbols into their live calls to help you work through a problem

Sam eMentor: OK. What sort of help do you need? Is there a specific problem you are stuck on?
Student Tom: I want to check how I use the Formula to solve equations!
Sam eMentor: you mean the formula x equals minus b plus or minus the square root of b squared minus 4 a c all over 2 a
Student Tom: yeah that's the one, I wasn't sure where you get the a, b and c from.
Sam eMentor: if you write a quadratic equation as ax2+bx+c=0 then these become our a,b and c to put into the x equals minus b plus or minus the square root of b squared minus 4 a c all over 2 a
Sam eMentor: so for example if we have 4x2+7x+3=0 we get a = 4, b=7 and c = 3
Sam eMentor: does that make sense?
Student Tom: Yeah that's great
Also do you know if we need to remember the formula for the exam?
Sam eMentor: You don't need to remember the formula as it is on the formula sheet. You do need to know how to use it though.
Student Tom: ok thats great :)
Sam eMentor: Do you want me to work through an example with you?
Student Tom: yes please
Sam eMentor: OK. Do feel free to stop us or ask us any questions if you are not sure.
Student Tom: ok
Sam eMentor: ok say you have x2-6x+4=0 then we have a = 1 b = -6 and c = 4
is that clear?
Student Tom: yeah
Sam eMentor: so putting these into the formula we get

(6 ± √ (-6)2-(4*1*4)) / 2*1

which equals (6 ± √ (36-16)) / 2

= (6 ±√20) / 2
Sam eMentor: ok?
Student Tom: one sec
Student Tom: yeah that makes sense
Sam eMentor: so working out the √20 and putting it in we get

x = (6 - 4.4721...) / 2 or (6 + 4.4721...) / 2

x = 0.764 or 5.236
Sam eMentor: which is correct to 3 d.p
Sam eMentor: is that ok?
Student Tom: Yeah that's great thanks

The Coaches will direct you to relevant Maths resources as appropriate

Sam eMentor: great! :)
You may want to look at one of our learning rescources on quadratic equations such as http://172.16.2.20/Repos/Content/8/Launch.html
Student Tom: oh thanks i will have a look later.
I am going to have to go now. Is it OK if I come back if I get stuck?
Sam eMentor: Sure just let us know. You can find this transcript saved under the Coaches section so if you need to refer back to it to find the link for example.
Student Tom: cheers
cya
Sam eMentor: cya and good luck !