Question

equation of tangent line
y=1-x/1+x at x=0

Answer 1

Differentiate the equation with respect to x, then evaluate the derivative at x=0 to get the slope of the tangent line.
Get the y-coordinates at x=0, i.e. sub. x=0 into the equation.
You have a point, and the slope of the tangent line, you get find the equation.

Answer 2

\[y=\frac{ 1-x }{ 1+x }\] ??

Answer 3

\[\frac{ d }{ dx }(\frac{ 1-x }{ 1+x })= \frac{ -2 }{ (x+1)^2 }\]

Answer 4

now substitute for x=0

Answer 5

so \[y=-2\]

Answer 6

btw, y does not equal -2