Function y = f (x) whose domain of definition is the interval [-4; 5].

Let’s define a function, the area of which is the interval [-4; five];

Let’s proceed as follows – compose a quadratic equation, the roots of which are the numbers -4 and 5.

Let’s use Vieta’s theorem:

b = – (-4 + 5) = -1;

c = -4 * 5 = -20;

Our equation:

x ^ 2 – x – 20 = 0;

Now let’s draw up an inequality, the solution of which is our interval:

x ^ 2 – x – 20 <= 0;

We transfer everything to the right side of the inequality:

-x ^ 2 + x + 20> = 0;

The> = 0 sign hints at the addition of a root sign:

y = (-x ^ 2 + x + 20) ^ (1/2) is our function.