U-Substitution on the TI-89: Raw Transcript

This is a video solving a u substitution problem step by step and
also demonstrating how my downloadable programs work in your TI 89 Titanium calculator
and other TI calculators for calculus and physics problems
and let’s get started uhm second alpha i n d e x the letters
and you press alpha to put eight and open and closed parenthesis
press enter and you’re into my menu you can scroll down or up to that u substitution
it’s all alphebetical and we’re going to get to u substitution here
enter our function you have to press alpha before you enter
anything in the entry lines here and we’re going to do
two times x times the
square root orange key
and then the over the times key x squared plus nine
press enter I always show you what you’ve entered
in case you’ve made a mistake I say it’s ok
and here’s your function we’re going to have to rewrite it
here’s the constant you have to take it outside the integral sign
take the x and put it over here by the dx and u equals x squared plus nine
and here’s the derivative anytime you have a constant here
you have to put it over and divide du by that constant
and leave the rest over here should be no numbers over here
notice this is the same as the previous x by dx
that’s why we rewrite it here’s the calculations
put em all down on your paper exactly like this
pretty complicated but when you take you notice when you have a square root
it’s to the one half and so therefore you’re using u to the one
half and you have to add one to that
which will be two halves which equals three halves and then
you have to divide by three halves that’s the way you integrate
and then of course don’t forget to uhm when you’re gonna when your dividing by
a fraction you always have to invert and multiply
here’s two thirds inverted from three halves or three over two
then you substitute back in for u and here’s your answer here
pretty neat huh every step calculus dot com
go to my site buy my programs
and pass your calculus