Let f be a function defined on the closed interval -3 on what intervals, if any, is f increasing

If f.) = 2x2 + 1, what is f(x) when x = 3?

Dafna1 [17]

Answer:

19

Step-by-step explanation:

f(x) = 2x^2 +1

Let x =3

f(3) = 2 (3)^2 +1

= 2 *9 +1

= 18 +1

= 19

5 0

4 years ago

Hurryyyy <br><br> An equation is modeled below Determine the solution for the equation.

crimeas [40]

Answer:

4

Step-by-step explanation:

:)

4 0

3 years ago

4. Simplify -6(3 – 5s + 12t – 2u)

Elan Coil [88]

-18 +30s -72t +12u is the answer

8 0

3 years ago

Suppose a home improvement contractor is painting the walls and ceiling of a rectangular room. The volume of the room is 288 cub

ratelena [41]

Answer:

The minimum cost is $17.30c

Step-by-step explanation:

Given

$V = 288$ --- Volume

$C_1 = 0.06$ --- cost of wall paint

$C_2 = 0.16$ ---cost of ceiling paint

Required

Minimum cost of paint

The volume is calculated as:

$V =xyz$

Substitute 288 for V

$288 =xyz$

Make z the subject

$z = \frac{288}{xy}$

The surface area is calculated as:

$Area = 2(yz + xz) + xy$

Because xy represent the dimension of the ceiling and the opposite of the ceiling (the floor) will not be painted. Hence, it does not require a coefficient of 2

The cost is:

$C = 0.06 * 2(yz + xz) + 0.16 * xy$

Substitute $z = \frac{288}{xy}$

$C = 0.06 * 2(y*\frac{288}{xy} + x*\frac{288}{xy}) + 0.16 * xy$

$C = 0.06 * 2(\frac{288}{x} + \frac{288}{y}) + 0.16 * xy$

$C = 0.12(\frac{288}{x} + \frac{288}{y}) + 0.16 * xy$

$C = (\frac{34.56}{x} + \frac{34.56}{y}) + 0.16 * xy$

$C = (\frac{34.56}{x} + \frac{34.56}{y}) + 0.16 xy$

Differentiate w.r.t x and y

$C_x = -\frac{34.56}{x^2} + 0.16y$

$C_y = -\frac{34.56}{y^2} + 0.16x$

By comparison: $x = y$

Set them equal to 0

$C_y = -\frac{34.56}{y^2} + 0.16x=0$

$-\frac{34.56}{y^2} + 0.16x=0\\$

Substitute x for y

$-\frac{34.56}{x^2} + 0.16x=0$

$0.16x=\frac{34.56}{x^2}$

Cross multiply

$0.16x^3 = 34.56$

$x^3 = \frac{34.56}{0.16}$

$x^3 = 216$

Take the cube root of both sides

$x = \sqrt[3]{216}$

$x = 6$

$x=y= 6$

Substitute 6 for x and for y in $C = (\frac{34.56}{x} + \frac{34.56}{y}) + 0.16 xy$

$C = (\frac{34.56}{6} + \frac{34.56}{6}) + 0.16 * 6* 6$

$C = (\frac{2*34.56}{6}) + 5.76$

$C = 11.52 + 5.76$

$C = 17.28$

$C = 17.3$ --- approximated

8 0

3 years ago

HELP PLZ THIS IS TIMED WILL GIVE BRAINLIEST

OlgaM077 [116]

(x² +9) and g(x) are factors of f(x).
That is, (x² +9)(g(x)) = f(x).

The roots of (x² +9) are roots of f(x). They are 3i and -3i.

The factor (x² +9) has degree 2, so f(x) has degree at least 2.

We cannot say anything about the x- or y-intercepts based on this information.

Imaginary roots usually come in even numbers (2, 4, etc.) for the polynomials we study. The information given here does not support the idea of 3 imaginary roots for f(x).

6 0

3 years ago