# Find the equation of tangent line

The tangent line equation calculator is used to calculate the equation of tangent line to a curve at a given abscissa point with stages calculation.

This example shows how to find equation of tangent line using the calculator :

equation_tangent_line(x^2+3;1), returns  [y=2+2*x]

### Equation tangent line, online calculus

#### Summary :

The tangent line equation calculator is used to calculate the equation of tangent line to a curve at a given abscissa point with stages calculation.

equation_tangent_line online

# Determine the equation of the tangent at a given point.

C is the graph of a differentiable function f at point a. The tangent to C at point A (a, f (a)) is the line through A and whose director coefficient is f'(a).

An equation of the tangent to C at point A (a; f (a)) is : y = f(a) + f'(a)(x-a).

It is through this approach that the function equation_tangent_line allows determine online the reduced equation of a tangent to a curve at a given point.

For example, to calculate the equation of the tangent at 1 of the function f: x-> x^2+3, enter equation_tangent_line(x^2+3;1) , after calculating the result [y=2+2*x] is returned.

The calculator shows the steps for determining the equation of the tangent.

# Draw the tangent function at a point

It is possible from the equation of the representative curve of a function to use the online graphing calculator for draw the tangent of a function at a point.

#### Syntax :

equation_tangent_line(function;number)

Note: x must always be used as a variable

#### Examples :

This example shows how to find equation of tangent line using the calculator :

equation_tangent_line(x^2+3;1), returns  [y=2+2*x]

Calculate online with equation_tangent_line (Find the equation of tangent line)