Math Is Fun Forum

Daniel123

Member

Registered: 2007-05-23

Posts: 663

Binomial Expansion (2)

A couple of queries

1. If x is so small that terms of x³ and higher can be ignored, show that:

(2+x)(1-3x)^5 is approximately 2 - 29x + 165x²

I get down to -15x² + 2 is approximately 165x² -2... but I might have gone wrong, and now what do i do?

2. If x is so small that terms of x³ and higher can be ignored, and
(2-x)(3+x)^4 is approximately a + bx + cx², find the values of the constant a, b and c. I get the same value for a as my textbook.. but different for b and c. anyone mind telling me what answer you get for it?

Thanks!

adam_dsutton

Member

Registered: 2007-09-12

Posts: 10

Re: Binomial Expansion (2)

Last edited by adam_dsutton (2007-09-20 07:36:26)