Respostas

2014-01-04T14:57:49-02:00
-1  \leq  cos x  \leq  1

-1  \leq   \frac{m-3}{4}   \leq  1

Separa as duas:
 * -1  \leq  \frac{m-3}{4}
m \leq -1

* \frac{m-3}{4}  \leq 1
m \leq 8

Resposta: -1  \leq m \leq 8
1 5 1
2014-01-04T15:52:03-02:00
Cos a = m - 3/4
-1 ≤ cos a ≤ 1
-1 ≤ m - 3/4 ≤ 1

m - 3/4 ≥ -1
m ≥ -1 + 3/4
m ≥ -4/4 + 3/4
m ≥ -1/4

m - 3/4 ≤ 1
m ≤ 1 + 3/4
m ≤ 4/4 + 3/4
m ≤ 7/4

S: {-1/4 ≤ m ≤ 7/4}