Question

F x =3x^2 -x/2 - 5 ;F(-2)=5 найтиF (-1)​

Answer 1

2x-5=-1 при х=2

Находим

f (-1) = f (2·2-5) = 22-3·2+5=3

или так:

замена переменной

2 х-5=t ⇒ x = (t+5) / 2

f (t) = ((t+5) 2/4) - 3· ((t+5) / 2) + 5

f (t) = (t2+4t+15) / 4

f (-1) = (1-4+15) / 4=3

Answer 2

To find F(-1) using the given function F(x) = 3x^2 - x/2 - 5, we substitute -1 for x in the equation and solve for F(-1).

F(x) = 3x^2 - x/2 - 5

Replacing x with -1:

F(-1) = 3(-1)^2 - (-1)/2 - 5 = 3(1) + 1/2 - 5 = 3 + 1/2 - 5 = 3 + 0.5 - 5 = 3.5 - 5 = -1.5

Therefore, F(-1) is equal to -1.5.