Question

quanto da essa equação??
$\frac{9}{25} + cos^{2}x = 1$

Answer 1

Resposta:

$cos^2(x) = 1 - \frac{9}{25}\\\\cos^2(x) = \frac{1*25-9}{25} \\\\cos^2(x) = \frac{16}{25}\\\\cos(x) = \pm \sqrt{\frac{16}{25}} \rightarrow cos(x') = + \frac{4}{5}; cos(x'') = - \frac{4}{5}\\\\x' = arcos(0,8); x'' = arcos(-0,8)\\\\x' = 0,64 rad\\x'' = 2,50rad\\\\ou\\\\x' = 36.87deg\\x'' = 143.13deg$