You are Here: Home

# can anybody help me pls?urgent watch

1. the function f(x) is defined by
f(x) = (2 + sin2x)/(2 + cosx)
Ignoring terms in x^3 and higher powers of x, obtain a quadratic approximation to the function f(x) for small values of x.
2. (Original post by islandguy)
the function f(x) is defined by
f(x) = (2 + sin2x)/(2 + cosx)
Ignoring terms in x^3 and higher powers of x, obtain a quadratic approximation to the function f(x) for small values of x.
use maclaurin's series after simplification
3. (Original post by islandguy)
the function f(x) is defined by
f(x) = (2 + sin2x)/(2 + cosx)
Ignoring terms in x^3 and higher powers of x, obtain a quadratic approximation to the function f(x) for small values of x.
(for small x) sin2x is approx 2x, cosx is approx 1-(x^2)/2 (mclaurin)

therfore

f(x)=(2 + 2x)(3 - (x^2)/2) = 6 - x^2 +6x - (x^3)

= 6 + 6x - x^2 (approx ignoring x^3 and higher)
4. (Original post by s-man)
(for small x) sin2x is approx 2x, cosx is approx 1-(x^2)/2 (mclaurin)

therfore

f(x)=(2 + 2x)(3 - (x^2)/2) = 6 - x^2 +6x - (x^3)

= 6 + 6x - x^2 (approx ignoring x^3 and higher)

sorry ignore that, misread the question, use mclaurin then use binomial expansion and simplify

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: April 17, 2004
Today on TSR

### Uni league tables

Do they actually matter?

### University open days

• Staffordshire University
Everything except: Midwifery, Operating Department Practice, Paramedic Undergraduate
Sun, 21 Oct '18
• University of Exeter
Wed, 24 Oct '18