Respostas

  • PeH
  • Ambicioso
2013-06-11T20:56:37-03:00

Sabemos que a secante é o inverso do coseno, isto é:

 

secx = \frac{1}{cosx}

 

Ou seja:

 

\text{Se} \ cos x = \frac{2}{7}, sec = \frac{7}{2} \\\\ \text{Temos que:} \\\\ sec x = \frac{7}{2} \\\\ sec x = \frac{m}{4} \\\\ \frac{7}{2} = \frac{m}{4} \\\\ 2m = 28 \\\\ \boxed{m = 14}

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