Raw Transcript

This video is gonna be on the equation of a tangent to the x point on a curve. This is the line when you have found the first derivative and you find the slope. This is the equation that is in the line at the point where you find the slope. This program I pretty neat, check it out on my website. Turn calculator on and clear screen to get to the menu of the program by pressing F1 8. Now add index 8 () to get to the menu of the program. Press 2nd Alpha, enter index, press alpha again to get back numbers and parentheses add 8 (). Here we are, select the equation of a tangent line, scroll down and press enter. It shows you what programs are added here. Enter the function 8*x to the 3rd power + 6*x+9

You can change or press ok if you want. Now you want a point, maybe at point 3, press Alpha 3 (it shows x=3). If youmade a mistake you can change it or say ok.

Function: F (x) = 8*x^3+6*x+9

F (x) = slope

= 24*x^2+6

The derivative o 6x is 6 f’ (x) =24*x^2+6

@ x= 3

F’ (3) = 24*”3”^2+6

=222

You have to go back and put 3 in the function to find y

Y = f (x) = 5s^2+6x+9

@ x = 3

Y = 8*’3”^3+6*”3”+9

=243

So (x,y) = (3,243)

Y=243 (222 is the slope)

243 = mx+b

243= 222(3) +b

B=243-666

=-423

Y = 222x+-423

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