You are Here: Home >< A-levels

A level maths help (binomial question)

Announcements Posted on
Why bother with a post grad course - waste of time? 17-10-2016
1. Hey guys i'm stuck on this question (1 +√ x )^3
my method is
3C0 x (1)^3 x (√x)^0 = 1 x 1 x 1 = 1
3C1 x (1)^2 x (√x)^1 = 3 x 1 x √x = 3√x
3C2 x (1)^1 x (√x)^2 = 3 x 1 x x^2
3C3 x (1)^0 x (√x)^3 = 3 x 1 x √x . x^3

What I'm struggling to understand is why (√x)^2 is 2√x rather than x
2. (Original post by Wisteria_xo)
Hey guys i'm stuck on this question (1 +√ x )^3
my method is
3C0 x (1)^3 x (√x)^0 = 1 x 1 x 1 = 1
3C1 x (1)^2 x (√x)^1 = 3 x 1 x √x = 3√x
3C2 x (1)^1 x (√x)^2 = 3 x 1 x x^2
3C3 x (1)^0 x (√x)^3 = 3 x 1 x √x . x^3

What I'm struggling to understand is why (√x)^2 is 2√x rather than x
It's not

just like
3. (Original post by Wisteria_xo)
Hey guys i'm stuck on this question (1 +√ x )^3
my method is
3C0 x (1)^3 x (√x)^0 = 1 x 1 x 1 = 1
3C1 x (1)^2 x (√x)^1 = 3 x 1 x √x = 3√x
3C2 x (1)^1 x (√x)^2 = 3 x 1 x x^2
3C3 x (1)^0 x (√x)^3 = 3 x 1 x √x . x^3

What I'm struggling to understand is why (√x)^2 is 2√x rather than x
3rd line = 3 x 1 x X =3X
4th line = 3 x 1 x X^(3/2) = 3X^(3/2)
3rd line = 3 x 1 x X =3X
4th line = 3 x 1 x X^(3/2) = 3X^(3/2)
I though that was wrong.. i was scared to say anything in case i got it wrong too ^-^

Register

Thanks for posting! You just need to create an account in order to submit the post
1. this can't be left blank
2. this can't be left blank
3. this can't be left blank

6 characters or longer with both numbers and letters is safer

4. this can't be left empty
1. Oops, you need to agree to our Ts&Cs to register

Updated: May 2, 2016
TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Today on TSR

A level maths

Which modules should I take?

Poll

All the essentials

Student life: what to expect

What it's really like going to uni

Essay expert

Learn to write like a pro with our ultimate essay guide.

Create a study plan

Get your head around what you need to do and when with the study planner tool.

Resources by subject

Everything from mind maps to class notes.

Study tips from A* students

Students who got top grades in their A-levels share their secrets