Raw Transcript
I’m going to demonstrate the log to a base x or rather the base you want on the titanium calculator, these are particularly difficult to remember them from months and months from week to week and I program them, so they are not easy but it will be easy if you studied every second of your life like a professor does. So let’s get started, we are going to press, put my code in to get to my menu, second alpha, you can see the black mark here on your screen which tell you, you can do letters and we are going to put in “index”, we have to press alpha again to get to the second numbers 8 and close parenthesis, it’s all in the instructions that I send you when you purchase my programs. And then we want to scroll down here, notice all the things you can do, all the different things in the menu, all in alphabetical order, we’re going to go down to log of x here and we are going to press enter and we’re going to get into log problems. I’m proud of this program because, well let’s do evaluate for instance, you can press the number before the program or scroll down to it, press the number, give you some examples so you’ll know what to enter and we are going to put in, you’ve got to press alpha before you add anything into these lines here and you need to put the log, the word log in there, let’s see if it happens, if it doesn’t happen that’s number 4 so we have to press the alpha maybe second alpha again and then put in log and then alpha, we are going to put in a number, so we are going to do log to the base 2 and let’s do 1 divided by 8 or 1/8 and it shows you what you’ve entered, you can change it or accept it, I say it’s ok, press number 1, you know it was supposed to take you right down on your paper and this is the way it is, you take the same base on both sides and so am taking log 2 or base 2 to the x here and then we are going to do base 2 to the 8 which is 3 and then because this is denominator you have to bring it to the numerator so it will make an exponent, so its 2 to the minus 3 and if they have the same base then the exponents are going to equal, so here we have X equals a minus 3. Let’s do another one. Let’s take log of… on the internet, people have said how do you do by hand, step by step for instance log 3 to the 15 and sometimes the answer is you can’t, you need the log tables or you need the calculator to do it, you cannot do things by hand, everything by hand, so even though they try to tell you that you can, show you different things, the real answer is you can’t do it by hand, you have to use a calculator and that’s the reason that Napier did the log tables in the first place to eliminate that. So let’s do log to the … lets go and put in log Alpha 3(15). You can see log3(15), I say it’s ok again I’m going to go one. Notice I told you that you have to use the calculator or table of logs to solve this and so the way you do that is you add the X=log3(15) and then you convert it to exponential form, 3 to the X equals 15 that’s the question but then you divide log of 15 by log of 3, and log of 15 in the calculator is 2.71, log of 3 is 1.1, so the answer is 2.465, so 3 to the 2.465 is equal to 15 and you can go back to another problem, you can also go back to the main menu but I’ll save that for another video. everystepcalculus.com, enjoy my programs they’re great.