Question

find the linearization of f(x)=cosx at x=pi/2

Answer 1

Find f ' (pi/2), that is the slope of the linearization. Then you need the point (pi/2, f(pi/2)) Then write an equation in point-slope form

f'(x) = -sin x

What is the -sin (pi/2)?

Find cos(pi/2)

Is this enough of a how to?

Answer 2

this = f(pi/2)+f'(pi/2)(x-pi/2)

if i remember the formula correctly
= cos (pi/2) + -sine pi/2(x - pi/2)
= 0 - 1(x - pi/2)

Answer 3

finalizing jimyrep's answer
\[\pi/2 - x\]