Find the equation of the line tangent to y=cosx at x=pi/6

Question

anonymous · Answer

if  a line has slope m then what would be the slope of the line perpendicular to it.??

anonymous · Answer

The opposite reciprocal of m

mertsj · Answer

1.  Find the first derivative of your function.
2.  That is the slope function.  Plug pi/6 into the slope function to find the slope of the tangent at pi/6
3.  Plug pi/6 into the original function and find y
4.  (pi/6,y) is a point on the tangent.
5.  Use the slope from step 2 and the point from step 4 and write the equation of the line using point-slope form.

anonymous · Answer

We didn't learn what a derivative is. All I know is I'm supposed to plug pi/6 back into the formula f(x)=cosx and then use the formula (y2-y1)/(x2-x1) with the coordinates (pi/6 , cospi/6) and (x , cosx)

mertsj · Answer

Then I would choose an x value close to pi/6 so that the slope would be more accurate.