Question

Y = 9x2 – 1 В каком интервале лежит x, если y = 8?

Answer 1

y = 9x2 – 1
8 = 9x2 – 1
8 + 1 = 9x2
9 = 9x2
1 = x2
x = 1
x < 2

Answer 2

To find the interval in which x lies when y = 8, you simply need to substitute y with 8 in the given equation and then solve for x. The equation is:

Y = 9x^2 – 1

Now, let's plug in y = 8:

8 = 9x^2 – 1

Next, add 1 to both sides to isolate the term with x^2:

9x^2 = 9

Now, divide both sides by 9 to solve for x^2:

x^2 = 1

To find x, take the square root of both sides:

x = ±√1

x = ±1

So, the value of x can be either +1 or -1. Thus, the interval in which x lies when y = 8 is (-1, 1).