Question

Para quais valores reais de m a equação sen x = 2m + 5 tem solução ?

Answer 1

$\mathsf{-1\le~sen(x)\le~1}\\\mathsf{-1\le~2m+5\le~1}\\\mathsf{-1-5\le~2m\le~1-5}\\\mathsf{-6\le~2m~\le~-4}$

$\mathsf{-\dfrac{6}{2}\le~\dfrac{2m}{2}\le~-\dfrac{4}{2}}\\\large\boxed{\boxed{\boxed{\boxed{\mathsf{-3\le~m\le~-2}}}}}$