Question

What is the local linearization of `F(x) = cos(x)` at a=pi/4?

Answer 1

`L(x)=sqrt2/2-sqrt2/2 (x-pi/4)`

Explanation:

`L(x)=f(a)+f'(a)(x-a)`
`F(a)=cos (pi/4)=sqrt2/2`
`F'(a)=-sin(pi/4)=-sqrt2/2`
`L(x)=sqrt2/2-sqrt2/2 (x-pi/4)`