Question

f: R -> R , f(x) =-x+2+1 . Calculati E=f(-1) - f(2)​

Answer 1

$f( - 1) = - ( - 1) + 2 + 1 = 1 + 3 = 4$

$f(2) = - 2 + 2 + 1 = 1$

$f( - 1) - f(2) = 4 - 1 = 3$

Answer 2

f : R ---> R
f(x) = -x+2+1 = -x+3.

E = f(-1)-f(2)

f(-1) = -(-1)+3 = 1+3 = 4.
f(2) = -2+3 = 1.

E = 4-1 = 3.