👤

Sa se calculeze cosinus din 9 grade cu 5 zecimale exacte.vreau rezolvare completa va roog

Răspuns :

cos 9° = sqrt(1/2+sqrt(5/32+sqrt(5)/32)) =0, 9876883405 ...



9°=π/20 radieani
cosx=cos(a)+(x-a)*(cosa) `/1!+...+cos(derivat de 5)*(x-a)^5/5!

Faci a=0
cosx =1-x*sin0/1-x²coso/2!+x^3/3!sin0 +x^4cos0/4!-x^5sin0/5!=
1-x²/2-0+x^4/24-0
1-(π/20)^2*1/2+ (π/20)^4/24-