# Thread: how to apply chain rule and product rule on Ti-89

1. ## how to apply chain rule and product rule on Ti-89

Hi to all great members

has anyone know a trick to apply these rules in a ti-89?

I can't really get the right answer for this equationx^2+4x+4)^2
which cane be done by the chain rule.

all the best.

2. Because you are mentioning the chain rule, you must be referring to derivatives. The TI-89 can easily take the derivative of a problem like the one you posted. It's under Calc -> Derivative, or something like that. The syntax I believe is find the derivative function on the 89 under calc, input the expression you want to be differentiated, then put a comma and then x. That tells the calculator that x is the variable of differentiation. If you want to apply it at a certain point you can put another comma and the point I believe. Either way, add a closing parenthesis.

3. Originally Posted by User Name
Hi to all great members

has anyone know a trick to apply these rules in a ti-89?

I can't really get the right answer for this equationx^2+4x+4)^2
which cane be done by the chain rule.

all the best.
see the screenshot ... calculator syntax is highlighted on the bottom line.

4. Originally Posted by Jameson
Because you are mentioning the chain rule, you must be referring to derivatives. The TI-89 can easily take the derivative of a problem like the one you posted. It's under Calc -> Derivative, or something like that. The syntax I believe is find the derivative function on the 89 under calc, input the expression you want to be differentiated, then put a comma and then x. That tells the calculator that x is the variable of differentiation. If you want to apply it at a certain point you can put another comma and the point I believe. Either way, add a closing parenthesis.
Thanks buddy, I know to find X we should add comma and than x on the end of the equation, is there anything else we can put there? like to find tangent can we like put x=2 to find normal and tangent?
Originally Posted by skeeter
see the screenshot ... calculator syntax is highlighted on the bottom line.
Thanks a lot!!!
now i know what was my mistake!

5. Originally Posted by User Name
... is there anything else we can put there? like to find tangent can we like put x=2 to find normal and tangent?

Thanks a lot!!!
now i know what was my mistake!
If you want to calculate the slope of the tangent for a specific x-value then you can add the x-value by using the "|" operator. That's the key directly below the equal sign. See attachment.

The syntax is highlighted in the input line.