<p>Y i'm in precalc and we just learned partial fraction decomposition. As far as I see, I'm doing everything right yet I'm getting the answers wrong. Does anyone have any tips.</p>
<p>Obviously, you are NOT doing everything right if you are getting everything wrong. Check for simple arithmetic mistakes you may have made. Remember that the steps for decomposing fractions with distinct linear factors, repeated linear factors, distinct quadratic factors, repeated quadratic factors, etc, are different. Also remember that the degree of the numerator has to be less than the degree of the denominator, otherwise, use division to rewrite the function beforehand.</p>
<p>Make sure you are multiplying the unknowns by the right factors.</p>
<p>i.e., if you have:
1/((x-1)(x-2))=A/(x-1)+B/(x-2)</p>
<p>make sure to make that:
1=A(x-2)+B(x-1)</p>
<p>and not</p>
<p>1=A(x-1)+B(x-2)</p>
<p>Also, remember to increase repeated linear factors' powers if you have any.</p>
<p>i.e.,</p>
<p>If you need to decompose 1/((x-1)(x-2)^3, set that equal to A/(x-1)+B/(x-2)+C/(x-2)^2+D/(x-2)^3</p>
<p>You may also be making factoring errors or arithmetic errors.</p>
<p>I can't think of anything else that you could do wrong really.</p>
<p>i hope you guys are right!! cuz if thts the case i just need to be more careful with my work</p>
<p>Look at the textbook and go through the rules very carefully, there are a few important subtle points.
Or you could just be doing something stupid, like looking at the answer key for the wrong section</p>
<p>(oh and just a heads up: partial fractions might seem like a pointless topic, but it's actually the basis for a really important method when you get to calc bc)</p>