Diff Clac

[dianzhang]

let f:(-pi/4 , pi/4) -> R , F(x) = tan(2x). A tangent to the graph of y=F(x) where x=a makes and angle of 70" with the positive direction of the x-axis. Find the possible values of a.

I started off by sketching the graph of y=tan(2x) realized there should be two possible answers within the domain of (-pi/4 , pi/4). but i dont know how do i continue on from there?
could anyone help?



mod edit: removed random poll and included it in the post

[Hutchoo]

I did this question yesterday:

Which question do you need answered?


As for the other question - tan(70*180/pi) is the gradient of the tangent.

now diff f(x), then find the x values for when the derivative of f(x) is equal to tan(70*180/pi) subject to the restriction of the domain. In other words, solve f'(x) = tan(70*180/pi)

[dianzhang]

did you find out how to do it?