Question

Determine o valor de sec 315°

Answer 1

sec x = 1 / cos x 

315 = 360 - 45 

cos(360 - 45) = cos 360 cos 45 - sen360 sen 45 = cos45 

sec 315 = 1 / cos45 

cos 45 = 1 / raiz(2) 

sec 315 = raiz(2)