Question

a tangente de um ânguloé 5/12 quanto vale o cosseno do ângulo​

Answer 1

Resposta:

$cosx=\frac{12}{13} }$

Explicação passo-a-passo:

sec²x = 1 + tg²x

$sec^2x=1+tg^2x\\sec^2x=1+(\frac{5}{12})^2 \\\\sec^2x=1+\frac{25}{144} \\\\sec^2x=\frac{144+25}{144} \\\\sec^2x =\frac{169}{144}\\\\cos^2x=\frac{144}{169}\\\\cosx=\sqrt{\frac{144}{169} }\\\\cosx=\frac{12}{13}$