Edexcel Mathematics Specimen paper · Paper 1 · Question 2

Specimen paper · Paper 1 · Question 2 · 8 marks

$2. (a) Show that the binomial expansion of 1 (4 + 5x) 2 in ascending powers of x, up to and including the term in x2 is 5 2 + x + kx2 4 giving the value of the constant k as a simplified fraction. 1 (b) (i) Use the expansion from part (a), with x = 10 , to find an approximate value for 2 Give your answer in the form p where p and q are integers. q (ii) Explain why substituting x = 1/10 into this binomial expansion leads to a valid approximation$

Next question