Edexcel Maths Pure Paper 2
(Yr1) Expanding (a+B) ^n using the binomial expansion formula? - (3-2x)^8 Find the binomial expansions
up to x^2
1.) 8C0 x(-2x)x(3^8) + 8C1x(-2x)x(3^7) + 8C2x(-2x)^2x(3^6)
2. (1 + 2x)^30 up to x^3
=30C0x(2x) + 30C1x(2x) + 30C2x(2x)^2 xeg( 1^28)+ 30C3x(2x)^3
Powers (x) go up
Coefficient (eg 1) goes down
Binomial expansion formula when n(power) is a negative number or a fraction - (1+x)^n = 1 + nx + n(n-
1)/2 (x^2) + n(n-1)(n-2)/3 (x^3) +...
Example
(1+x)^-3 up to x^3
=1 - 3x +(-3(-3-1)/2 (x^2) + (-3(-3-1)(-3-2) /3 (x^3)
=1 - 3x + 6x^2 - 10x^3
(if it is not 1 take it outside of the bracket, everything inside will be divisible by that )
How do you calculate modulas functions? - X? = solve for x algebraicly
Y? = line crosses Y axis, so sub x for 0
| Negatives | become | Positives |
(Yr1) Expanding (a+B) ^n using the binomial expansion formula? - (3-2x)^8 Find the binomial expansions
up to x^2
1.) 8C0 x(-2x)x(3^8) + 8C1x(-2x)x(3^7) + 8C2x(-2x)^2x(3^6)
2. (1 + 2x)^30 up to x^3
=30C0x(2x) + 30C1x(2x) + 30C2x(2x)^2 xeg( 1^28)+ 30C3x(2x)^3
Powers (x) go up
Coefficient (eg 1) goes down
Binomial expansion formula when n(power) is a negative number or a fraction - (1+x)^n = 1 + nx + n(n-
1)/2 (x^2) + n(n-1)(n-2)/3 (x^3) +...
Example
(1+x)^-3 up to x^3
=1 - 3x +(-3(-3-1)/2 (x^2) + (-3(-3-1)(-3-2) /3 (x^3)
=1 - 3x + 6x^2 - 10x^3
(if it is not 1 take it outside of the bracket, everything inside will be divisible by that )
How do you calculate modulas functions? - X? = solve for x algebraicly
Y? = line crosses Y axis, so sub x for 0
| Negatives | become | Positives |
