# Math Help - Help please logs!!

Hi Can someone please explain how do I calculate the following:

2. Originally Posted by ticktack
Hi Can someone please explain how do I calculate the following:
i will show you how they calculated the first one (when time = 0), the others are similar.

recall that: $\log_a (xy) = \log_a x + \log_a y$

also recall that: $\log_x \left( x^a \right) = a$

So for t = 0, we have $1.995 \times 10^{5}$ variable cells.

So, $\log_{10} \left( \mbox {variable cells} \right) = \log \left( 1.995 \times 10^5 \right)$

................................... $= \log 1.995 + \log 10^5$

................................... $\approx 0.3 + 5$

................................... $= 5.300$

of course, for $= \log 1.995$, you plug that into your calculator. now do the rest in the same way

3. thanxxxxxxx so much

Another question, how would I plot the following points on a graph with the axis been given....

4. Originally Posted by ticktack
thanxxxxxxx so much

Another question, how would I plot the following points on a graph with the axis been given....
those axis aren't large enough to plot all the data given, but otherwise plotting is easy. let the horizontal axis be time and the vertical axis be the cell density. for each row, you have a time and a cell density, each row will make one point. pick a row, go to the horizontal axis and find the time, then move up in a vertical line on till you get to the horizontal line that represents the corresponding cell density.

basically what you are doing is drawing a vertical line from the time on the horizontal axis and a horizontal line from the cell density on the vertical axis, and wherever the lines meet, that's where you mark a point. connect all the points with a line and there's your graph