Alg_Complete

# We could choose x 0 to get the value of a but thats

This preview shows page 1. Sign up to view the full content.

This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: always do that. [Return to Problems] (b) 9 - 9x 2x + 7 x - 4 2 Okay, in this case we won’t put quite as much detail into the problem. We’ll first factor the denominator and then get the form of the partial fraction decomposition. 9 - 9x 9 - 9x A B = = + 2 x + 7 x - 4 ( 2 x - 1)( x + 4 ) 2 x - 1 x + 4 2 © 2007 Paul Dawkins 273 http://tutorial.math.lamar.edu/terms.aspx College Algebra In this case the LCD is ( 2 x - 1) ( x + 4 ) and so adding the two terms back up give, A ( x + 4 ) + B ( 2 x - 1) 9 - 9x = 2x + 7 x - 4 ( 2 x - 1)( x + 4 ) 2 Next we need to set the two numerators equal. 9 - 9 x = A ( x + 4 ) + B ( 2 x - 1) Now all that we need to do is correctly pick values of x that will make one of the terms zero and solve for the constants. Note that in this case we will need to make one of them a fraction. This is fairly common so don’t get excited about it. Here is this work. x = -4 : 45 = -9 B 1 x= : 2 9 = 2 æ9ö Aç ÷ è2ø Þ B = -5 Þ A =1 The partial fraction decomposition for this expression is,...
View Full Document

## This note was uploaded on 06/06/2012 for the course ICT 4 taught by Professor Mrvinh during the Spring '12 term at Hanoi University of Technology.

Ask a homework question - tutors are online