Question

Функция задана формулой y=x²-4. а)найдите значение функции при x= 0; -3. б) При каких значениях x значение функции равно -3

Answer 1

A) y=0^2-4=0-4=-4
    y=(-3)^2-4=9-4=5
b) -3=x^2-4
     x^2=-3+4=1
     x=1
     

Answer 2

To find the values of the function for specific values of x, simply substitute the given x-values into the function.

a) Find the values of the function when x = 0 and x = -3:

a.1) When x = 0: y = x² - 4 y = 0² - 4 y = -4

So, when x = 0, the value of the function is -4.

a.2) When x = -3: y = x² - 4 y = (-3)² - 4 y = 9 - 4 y = 5

So, when x = -3, the value of the function is 5.

b) To find the values of x when the function is equal to -3, set the function equal to -3 and solve for x:

-3 = x² - 4

Now, we need to solve for x. Let's rearrange the equation:

x² = -3 + 4 x² = 1

To isolate x, we take the square root of both sides (remembering that both positive and negative square roots are possible):

x = ±√1

x can be either +1 or -1.

So, when the value of the function is -3, the corresponding values of x are +1 and -1.