Tangent Line

WARNING: The answer for this command is displayed at the bottom of the graphing screen. Some part of the formula may exceed the dimension of the screen.

Suppose we want to use the calculator to compute the equation of the tangent line for the function at x=4.

• Press and enter the function into Y₁.
  • Make sure the function is turned on.

• Set thewindow. Be sure that the x-value, you want to compute the derivative for, is between the X-min and X-max values. For this problem I used
  X-min = -10, X-max = 10, Y-min = -10, and Y-Max = 60
  
  • Note: The y-scale is not important. The Zoom Fit option may be used for these values.

• Press
• Press
• Choose 5:Tangent(.
• Enter the value of x where you want to compute slope of the tangent line. For the example this is 4.
• Press

The calculator should now display the following.

The answer is on the bottom line of the screen.

y = 16x − 23