Question

PLEASE HELP! MEDAL! @solomonzelman

Answer 1

\(\large\color{#000000 }{ \displaystyle f(x)=\sqrt{x^2+9} }\) \(\large\color{#000000 }{ \displaystyle a=-4 }\)

Answer 2

basicaly, you are finding the tangent line to the function, at the point x=a, AND THEN you are using this tangent line to approximate f(a).

Answer 3

ok, so first find the derivative...