4 Major Concepts I understood
In class I have understood how to find the inverse of a function
I learned that the inverse have same inputs and outputs but switched
so its like the inputs of f(x) turned into the outputs of f^-1(x) the same as the outputs of f(x) turned into the input of f^-1(x) so to find out the invese we just have to change the equation so that f(x)=x and x=y
I have also understood the "one-to-one" concept of inverses
to have one-to-one functions the function and it inverse whould pass the vertical line test
you would know how the inverse would pass the vertical line test by doing a horizontal line test on the parent function
I have also learned how to solve logarithms, well some of them
I know that to solve the logarithms you have to find the unknown by leaving it by itself
you have to take the log with the base equal to what you are trying to get so you can get 1
for example: 5^-x=25
to solve for x you have to first take the log base of 5 to both sides of the equations to leave -x by itself and then you get -x=log base of 5(5)^2 which will leave you with x=-2
Another concept I understand is the easist thing, in my opinion, about inverse
That for evry time you put an inverse into the equation to its parent function you will ALWAYS get x, algebraically it means f(f^-1(x))=x as well as f^-1(f(x))=x
This is almost everything that I understand about Logarithms and Inverse, good thing we were only asked to write about 4 things.
Things That I did NOT understand
Well I did not understand MANY things
Just as many of you, I do not really understand how to graph logarithms without a graphing calculator, i think that it is hard
I also did not understand the homework C2, I did not know how to solve 80% of the problems.
If you need help on how to graph logarithms, Jesus kind of explained it on my blog! ohh and if you needed help on #35, this is how you do it.
ReplyDeleteRocio and Jesus helped me with #35, which is similar to 36 as well.
Do the reciprocal of e ^ -x to the original equation given to you.
Then, multiply both sides by e^x in order to get 1/e^x to become "1". Now you should have e^2x+1 = 3e^x.
Next you subtract 3e^x to both sides and get e^2x-3e^x+1= 0.
Now its in the format of a quadratic equation.
You then have to complete the square
Treat e^x as just x
After completing the square you get
3 +/- (square root) 5 / 2.
"After that you take the natural log of everything to cancel out the e and you have your answer"
You should put some of the questions you need help with on C2 so people can help you on those specific problems.
myself, like you and others in class.. do not know how to graph logarithm. but i took a look back at the "intro to logarithms" worksheet and found out that the log graphs are simply just an inverse to an exponential function graph.
ReplyDeletewhat i think is that we must turn the log equation back into exponential form first then graph it.. in order to see the log (or inverse) of the exponential graph.
:D
If you need help with graphing logs, you should read Jesus Tejeda's blog cause he posted up something to help everyone who doesn't understand how to graph logs (including me)! :D
ReplyDeleteTo graph logs all you need to do is change it to exponential form. Once it is in that form it is easy to graph them.
ReplyDeleteHello, well i had trouble with the same topics, but reading other people's posts has helped me. I think you would find them useful too!
ReplyDeleteuuhhh.... even after reading your comments i still dont know lol.
ReplyDeleteERik, you, and I should join forces and study together(:
man when you know how to do that tell me please.
remember i also asked for the domain and range...?