Skip to content
MathsGenie logo
Open app

Course home

  1. A Level
  2. Maths CCEA
  3. Question bank

Binomial Expansion

EasyMedium
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596
Question 36

The intensity of light LLL measured at a depth rrr inside a specific mineral solution is modeled by the function

L(r)=(4+αr)−2,∣αr∣<4 L(r) = (4 + \alpha r)^{-2}, \quad |\alpha r| < 4 L(r)=(4+αr)−2,∣αr∣<4

where α\alphaα is a non-zero attenuation constant. The series expansion for this model is given by

L(r)=A+Br+Cr2+Dr3+… L(r) = A + Br + Cr^2 + Dr^3 + \dots L(r)=A+Br+Cr2+Dr3+…

where A,B,CA, B, CA,B,C and DDD are constants.

a.

Find the value of AAA.

[1]
b.

Given that C=−9BC = -9BC=−9B

show that α2−24α=0\alpha^2 - 24\alpha = 0α2−24α=0.

[4]
c.

Hence (i) find the value of α\alphaα (ii) find the value of DDD.

[3]

Binomial Expansion Questions

  1. A Level
  2. /Maths
  3. /Binomial Expansion