3 answersLast reply by: Professor Selhorst-Jones Thu Sep 6, 2012 4:13 PMPost by Nigel Hessing on June 2, 2012I don't understand why is 3 x (4, 5) = 12,5 shouldn't it be 12, 15? 1 answerLast reply by: Debora OppongSat Sep 1, 2012 1:26 PMPost by Leili Ghazizadeh on August 17, 2012This video has some issues, could you please make it work? slide after 1 minute and 30 seconds doesn't go forward and it's stuck. 2 answersLast reply by: James PelezoSun Mar 24, 2013 3:12 PMPost by Al Khurasani on October 8, 2012Shouldn't the SI unit of Volume be "Cubic Metre" ? "In the International System of Units (SI), the standard unit of volume is the cubic metre (m3)"[WikiPedia] 0 answersPost by James Pelezo on March 24 at 03:26:44 PMSignificant Figures rule: 'zeros to the right of sig figs are sif figs'... What if one is measuring astronomical distances such as the distance from the earth to the sun? It is generally accepted that, D(avg)= 93,000,000 miles... Are the six trailing zeros sig figs, or are they there just for indicating magnitude? Sig figs, as I understand, are relative indications of the accuracy of the measuring instruments being used. Astronomical distances that vary with time are very large averages and are typically rounded to millions or billions of units specified. To specify the trailing zeros in this example as sig figs would require the distance from the earth to the sun to be 93,000,000 miles 365-days per year. Questionable at best.

### Math Review

• Science is almost always done in the metric (SI) system. This course will only use this system of units.
• Scientific Notation: We can condense numbers that would require many zeros to write by using powers of 10. For example: 0.027 = 2.7·10−2 and 4700 = 4.7 ·103.
• Significant Figures: How many digits we have in a number tells us how much we can "trust" the number. Just because your calculator gives you a lot of digits does not mean you can trust it more than the data you started off with.
• Trigonometry: If you don't remember trigonometry, go look up a quick refresher on the basics. We won't need very complex trig in this course, but we use the core ideas a lot.
• Vectors: A vector is a way to show both length and direction. Equivalently, we can name a vector by naming its components.
• When working with vectors, we add them together component-wise.
• If you multiply a scalar (a single number) with a vector, it just multiplies each component of the vector. [Notice that there is no definition for multiplying two vectors together. It wouldn't make sense!]
• We can find the length of a vector by using the Pythagorean Theorem. If v = (vx , vy), then its length is | v | = √{vx 2 + vy 2}.

## Math Review

Lecture Slides are screen-captured images of important points in the lecture. Students can download and print out these lecture slide images to do practice problems as well as take notes while watching the lecture.