Wednesday, March 12, 2008

Products of a Monomial and a Polynomial -March 12

Today in class we learnt how to multiply monomials and polynomials. Basically all you have to do is multiply the monomial outside of the brackets by the polynomial inside the brackets.
Ex: Expand
3a(4a-3b)
=12a²-9ab

We also learnt how to simplify these expressions. To simplify an expression you, first, expand the expression like we have already done and then, secondly, collect like terms.
Ex: Expand and Simplify
4x(2x²+ 5x -3) –(2x²-7)
=8x³+20x²-12x-2x²+7
=8x³+18x²-12x+7

The final thing that we learnt to do today was multiplying binomials. When multiplying binomials you use the F.O.I.L. method. The F.O.I.L. method stands for multiplying the First two terms, then multiplying the Outside two terms, then multiplying the Inside two terms, and, finally, multiplying the Last two terms.
Ex: Find the product of the binomials
(x+6)(x+8)
=x²+8x+6x +48 <----(F.O.I.L. method)
=x²+14x+48 <----( you have to collect like terms here too.)

The assignment for today was:
pg.107, questions 1-29 odd and pg.108, questions 32-43 and 45-67

2 comments:

the Mendicant Crow said...

Your use of examples made this post very easy to follow and understand, even for someone like myself who hasn't done any calculus for almost a year. It was a good refresher for me, and would be willing to link to this post if I were ever teaching pre-calc. to give students an overview on this lesson.

Nicole L. (Mentor) University of Regina, email: little1n@uregina.ca, blog: http://nicolelittle.wordpress.com

Ste. Anne Collegiate - PreCal 20S 2008 said...

Well done Rob! Mrs. Remple