How do you find the tangent line approximation to #f(x)=cos(x)# at #x=pi/4# ?
In this problem we need to follow 5 steps.
1) Find the value of y given the x-value of
2) Find the derivative of
3) Substitute in the x-value of
4) Substitute the slope and the
5) Use the y-intercept and slope to find the equation of the of the tangent line.
Point of tangency: