Find the equation of the tangent line to the curve.

Hi guys,

Could someone take a look at my work.. im lost.

Problem:

Code:

`Find the equation of the tangent line to the curve `

y= 4 tan x at the point ( pi/4 , 4).

The equation of this tangent line can be written in the form y = mx+b

my work..

Code:

`using y-y1 = m(x-x1)`

y - 4tan(x) = 4tan(x- (pi/4))

y - 4tan(x) = 4tan(x) - (pi tan (x))

y = 8tan(x) - pi tan(x)

m = 8tan(x)

b = pi tan (x)

Where did I go wrong? How do I get the equation from the point and the tangent line?