determiner-la-valeur-exacte-de-sin-85-4-

Question Number 73608 by mathocean1 last updated on 13/Nov/19

determiner

la valeur exacte de \sin (\frac{85 Π}{4})

Commented by mathmax by abdo last updated on 13/Nov/19

s i n (\frac{85 π}{4}) = s i n (20 π + \frac{5 π}{4}) = s i n (\frac{5 π}{4}) = s i n (π + \frac{π}{4}) (20 π i s p e r i o d)

= - s i n (\frac{π}{4}) = - \frac{\sqrt{2}}{2}

Commented by kaivan.ahmadi last updated on 13/Nov/19

s i n (21 π + \frac{π}{4}) = s i n (π + \frac{π}{4}) = - s i n (\frac{π}{4}) = - \frac{\sqrt{2}}{2}

Commented by mathocean1 last updated on 14/Nov/19

thank you sir

Commented by mathocean1 last updated on 14/Nov/19

thank you sir

Commented by mathmax by abdo last updated on 14/Nov/19

y o u a r e w e l c o m e .