Question

usando a formula F (a) =a(a+1)/2 para calcular f(-4) ,f(-6) ,f(-1,2) ?

Answer 1

f(a) = $a \ . \ \frac{(a + 1)}{2}$


Substituindo "a" pelos valores propostos, temos:


f(-4) = $-4 \ . \ \frac{(-4 + 1)}{2}$

f(-4) = $-4 \ . \ \frac{(-3)}{2}$

f(-4) = $\frac{(12)}{2}$

f(-4) = 6



f(-6) = $-6 \ . \ \frac{(-6 + 1)}{2}$

f(-6) = $-6 \ . \ \frac{(-5)}{2}$

f(-6) = $\frac{(30)}{2}$

f(-6) = 15



f(-1,2) = $-1,2 \ . \ \frac{(-1,2 + 1)}{2}$

f(-1,2) = $-1,2 \ . \ \frac{(-0,2)}{2}$

f(-1,2) = $\frac{(0,24)}{2}$

f(-1,2) = 0,12