Binomial expansion of (1+4x)^5 up to x^2

This question can be treated like a normal binomial expansion question which is commonly seen at A level. The standard binomial expansion is (1+x)n = 1 + nx + (n(n-1)(x2))/2! where 2! is 2 factorialSo in this question let u=4x, n=5(1+u)^5 = 1 + 5u + (5)(4)(u2)/(2)(1)(1+u)5= 1 + 5u + 10u2now we need to substitute in u=4xso (1+4x)5 = 1 (5)(4)x + 10(4x)2(1+4x)5=1+20x+160x2

KI

Related Maths A Level answers

All answers ▸

Particles P and Q of masses 0.4kg and m kg are joined by a light inextensible string over a smooth pulley. When released Q accelerates downward at 2.45ms^-2. Find m.


f(x)=ln(3x+1), x>0 and g(x)=d/dx(f(x)), x>0, find expressions for f^-1 and g


What is the equation of the tangent to the curve y=x^3+3x^2+2 when x=2


How do you differentiate x^x?