All categories

3 years ago

If f(x) = 2x2 - x, find f(-3). 15 21 39

Mathematics

2 answers:

elixir [45]3 years ago

5 0

I believe its 21 sorry if im wrong

fenix001 [56]3 years ago

4 0

Its C on edge but the answer is 21

You might be interested in

!!!Please help will give the brainliest, and please do not put in a silly answer because you want some points or I will report y

Amanda [17]

Answer:

In short, they are all quadrilaterals.

Step-by-step explanation:

Rectangle:

- Every angle equals 90 degrees

- Opposite sides are equal and parallel

Square:

- Every angle equals 90 degrees

- Opposite sides are equal and parallel

- Diagonals within the square are perpendicular

Parallelogram:

- Opposite sides are equal and parallel

- Opposite angles are equal

- Any two angles next to each other have to equal 180 degrees, since it would be a line

Rhombus:

- Opposite angles are equal

- All sides are equal

- Opposite sides are parallel

- Diagonals within the square are perpendicular

- Any two angles next to each other have to equal 180 degrees, since it would be a line

Trapedzoid:

- There is only one pair of parallel lines

Kite:

- There are two pairs of equal signs

- There are two equal angles

- You can look at it like two equal triangles glued together

Really hope this helped you!

7 0

3 years ago

Naomi can spend up to $18.00 for a trip to the bowling alley. The cost per game is $3.25, and shoe rental for the day is $1.50.

Alja [10]

Answer:

The answer for this question is D

Step-by-step explanation:

because x represents the number of games which is unknown plus 1.50 for the shoe rental

3 0

3 years ago

Write 0.09 as a simplified fraction

Illusion [34]

9/100, let me know if this helps.

4 0

3 years ago

307692 rounded to nearest hundredth

ZanzabumX [31]

Are you thinking of hundreds? If so, then it would be 307700.

7 0

3 years ago

A radio telescope has a parabolic surface, as shown below.

krek1111 [17]

OK, so the graph is a parabola, with points x=0,y=0; x=6,y=-9; and x=12,y=0

Because the roots of the equation are 0 and 12, we know the formula is therefore of the form

y = ax(x - 12), for some a

So put in x = 6

-9 = 6a(-6)

9 = 36a

a = 1/4

So the parabola has a curve y = x(x-12) / 4, which can also be written y = 0.25x² - 3x

The gradient of this is dy/dx = 0.5x - 3

The key property of a parabolic dish is that it focuses radio waves travelling parallel to the y axis to a single point. So we should arrive at the same focal point no matter what point we chose to look at. So we can pick any point we like - e.g. the point x = 4, y = -8

Gradient of the parabolic mirror at x = 4 is -1

So the gradient of the normal to the mirror at x = 4 is therefore 1.

Radio waves initially travelling vertically downwards are reflected about the normal - which has a gradient of 1, so they're reflected so that they are travelling horizontally. So they arrive parallel to the y axis, and leave parallel to the x axis.

So the focal point is at y = -8, i.e. 1 metre above the back of the dish.

5 0

2 years ago