Question

A diferença entre o valor máximo e mínimo da função y = -7 -cos x é igual a: *
A) 2
B) 1
C) 0
D) -1
E) -2​

Answer 1

$\Large\boxed{\begin{array}{l}\sf Im=[-7+[-1],-7-[-1]]\\\sf Im=[-7-1,-7+1]\\\sf Im=[-8,-6]\\\sf v_{m\acute aximo}=-6\\\sf v_{m\acute inimo}=-8\\\sf v_{m\acute aximo}-v_{m\acute inimo}=-6-[-8]\\\sf v_{m\acute aximo}-v_{m\acute inimo}=-6+8\\\sf v_{m\acute aximo}-v_{m\acute inimo}=2\\\huge\boxed{\boxed{\boxed{\boxed{\sf\red{\maltese}~\blue{alternativa~A}}}}}\end{array}}$