Question

Find an equation of the tangent line to the curve at the given point.
y = 4e^x cos x, (0, 4)
y'=4

Answer 1

ok... it appears that you have the slope at the point (0, 4) so you just need to find the equation of the tangent

then slope intercept form is

y = mx + b

or in your question

y = 4x + b

substitute x = 0 and y = 4 to find the value of b, and the equation of your line