Derivatives with a TI-86 calculator?

Question

Can anyone explain to me how to take the first and or second derivative of a function with a Ti-86 calculator.

thanks

Answer 1

I have a TI-84 but I'm sure the syntax must be the same.

Under the Math category, towards the bottom you will find the NDERIV() function. Select that and enter in: NDERIV(f(x),x,c) where f(x) is the function you are evaluating, with respect to x (it should always be x, unless you are using another variable), at point c.

For example, to evaluate derivative of y=x^2 at 3, you would enter NDERIV(x^2,x,3) and simply hit enter.

An alternate method is to graph the function and select dy/dx calculation at the point you want to evaluate the derivative.

I know that on the TI-89 a "|" is used to separate the first two arguements from "c", try that if it doesn't work.

Note that the calculator finds the derivative by calculating the slope +/- 0.01 from the point you choose, not by evaluating limits. This can lead to answers that are completely wrong, use discretion when you choose to use the NDERIV function.

Answer 2

just do it by hand its easy....say you have 6x raised to the 2nd power just take the exponent and multiply it with 6 the # before the x then you get 12 then take the exponent and subtract 1 which equals 12x, if you want second derivative then do it again....in this cas it would equal 12

Answer 3

sorry i'd help if i could