Aim: Be able to analyse and model engineering situations and solve problems using algebraic methods 14/08/2022 Louis Mbua Egbe PhD Teach Engineering & Technology Solutions Ltd © 1 Polynomial division is done as long division. Factor Theorem states that if x= a is a root of the equation f(x) = 0, then x-a is a factor of f(x). Thus, a factor of x-a corresponds to a root of x=a 14/08/2022 Louis Mbua Egbe PhD Teach Engineering & Technology Solutions Ltd © 2 It is of importance to know the remainder of a polynomial division because if the remainder is zero, it means that that divisor is a factor of the polynomial, and therefore , crucial in factorising that particular polynomial. The Remainder Theorem states: If (ax2 +bx +c) is divided by (x-p), the remainder will be (ap2 + bp + c) This is true for cubic and higher order equations. So we write: 14/08/2022 Louis Mbua Egbe PhD Teach Engineering & Technology Solutions Ltd © 3 If (ax3 +bx2 +cx + d) is divided by (x-p), the remainder will be (ap3 + bp2 + cp + d) 14/08/2022 Louis Mbua Egbe PhD Teach Engineering & Technology Solutions Ltd © 4 Partial Fractions 1. 2. 3. Partial fractions are a reverse process of polynomial division to convert them into fractions of its factors. In order to work out the solution of this reverse process into partial fractions: The denominator must factorise. The numerator must be at least one degree less than the denominator. When the degree of the numerator is equal to or higher than denominator, the numerator must be divided by the denominator by long division. 14/08/2022 Louis Mbua Egbe PhD Teach Engineering & Technology Solutions Ltd © 5 1. 2. 3. There are three types of partial fractions with denominators containing: Linear factors Repeated linear factors Quadratic factors 14/08/2022 Louis Mbua Egbe PhD Teach Engineering & Technology Solutions Ltd © 6 Linear Types Expression: f(x) /(x+a)(x-b)(x+c) Partial fraction form: A/(x+a) + B/(x-b) + C/(x+c) 14/08/2022 Louis Mbua Egbe PhD Teach Engineering & Technology Solutions Ltd © 7 f(x)/(x+a)3 Form of partial fractions: A/(x+a) + B/(x+a)2 + C/(x+a)3 For Quadratic factors, form of partial fractions: f(x)/(ax2 + bx + c)(x+d) = (Ax +B)/(ax2 + bx + c)(x+d) + C/(x+d) 14/08/2022 Louis Mbua Egbe PhD Teach Engineering & Technology Solutions Ltd © 8