Question

se considera numarul a=2/1×3+2/3×5+...+2/49×51. stabiliti daca a apartine intervalului (1/2,1​

Answer 1

Răspuns:

Explicație pas cu pas:

2/1×3 = 1 - 1/3

2/3×5 = 1/3 - 1/5

.............

2/49×51 = 1/49 - 1/51

___________

2/1×3 + 2/3×5 +...+ 2/49×51 =  1 - 1/3 + 1/3 - 1/5 + ... + 1/49 - 1/51

a = 1 - 1/51 = 51/51 - 1/51 = 50/51

1/2 < 50/51 < 1

51/102 < 100/102 < 102/102 adevarat