Given f(x)=-x2, find f(3)

Which method can be use to solve all quadratic equation? explain

Delvig [45]

The quadratic formula, i need a pic

3 0

3 years ago

A rectangular swimming pool that is 10 ft wide by 16 ft long is surrounded by a cement sidewalk of uniform width. If the area of

mars1129 [50]

The pool has area $160\,\mathrm{ft}^2$ .

Let $x$ be the width of the sidewalk. Then the combined area of the pool and sidewalk is $(10+x)(16+x)=160+26x+x^2$ , so that the area of the sidewalk alone is $26x+x^2$ .

We're told this area is $155\,\mathrm{ft}^2$ , so

$26x+x^2=155\implies x^2+26x-155=(x-5)(x+31)=0\implies x=5$

6 0

3 years ago

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Susan Bought a soccer ball for her brother. She wants to fool him by putting the ball into a box before wrapping it. The balls c

frutty [35]

Answer:

Ball cannot be fit inside the box.

Step-by-step explanation:

Given:

Circumference of ball = 26 inches

Dimension of box = 8.25 in x 8.25 in x 8.5 in.

We need to find the whether ball gets fits inside the box.

First we will find the Diameter of ball.

Circumference of ball is given so we will find radius of the ball.

Circumference of the sphere is equal to 2 times π times radius.

framing in equation form we get;

$2\pi \times r =26\\\\r= \frac{26}{2\pi}= 4.14\ in.$

Now we will find the Diameter of the ball.

Diameter of ball is equal to 2 times radius.

framing in equation form we get;

Diameter of ball = $2\times 4.14 = 8.28\ in$

Now given that two parallel sides of box has dimension which is 8.25 in.

Since Dimension of box is smaller than diameter of the ball.

Hence we can say that ball cannot be fit inside the box.

5 0

3 years ago

The lines below are parallel. If the slope of the green line is -3, what is the

siniylev [52]

Answer:

m=-3

Step-by-step explanation:

Since the lines are parallel to each other, their gradients are equal.

∴ gradient of green line = gradient of red line

∴ m = -3

6 0

2 years ago

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A#27 - Surface Area

ollegr [7]

Answer:

Step-by-step explanation:

Surface area is finding the area of each face and adding them up. So a cube will have 6 faces, each of them a square. So find the area of one face and you can just add it 6 times. If the faces are not all the same you have to find them seperately. I won't do all of your questions, but let me know if you need help with a specific one

1) there are two trianglular faces and three rectangular ones. The triangles are the same so let's do those. They have the base and height of 4 and 3, so area of both will be .5*4*3 = 6, so together that makes 12. now the three rectangular sides. Right away you can see there is a 3 by 10 one and a 4 by 10 one. These ahve areas of 30 and 40 respectfully. The final face has one length of 10 but the last one is actually the last side of the right triangle faces. Use the Pythagorean theorem to find it, it word out to be 5. So now we know the last face is 10 by 5 which means an area of 50. So let's add them all together. 5 faces total with areas of 30, 40, 50, 6 and 6. Adding them together makes 136.

If you don't get how I did any of that let me know. In general it's a good idea to mark every face and then find what their sides are. I'd be happy to help with specific problems.

Now the second part, again I will do the second one because cones are little less intuitive. a cone has two faces, the circular base and the actual cone shape. the surface area of the cone shape is pi*r*L where r is the radius of the base and L is the length of one of the slanted sides. Now, let's find the area of the two faces. Area of a circle is pi*r^2 so that's pi*4^2 = 16*pi in number 2. Then the area of the cone part is pi*r*L = pi*4*14 = 56*pi. now we sum all the areas of the faces up and get 16*pi + 56*pi = 72*pi.

Again, I'm happy to answer specific questions, so let me know if you have any. just keep in mind what I told you so far, find each face, then find each face's area then sum them up. For cylinders the tubes turn into rectangles where one side is the length of the tube and the other is the circumference, while cones fave two faces, the circular base and the cone shape itself with an area of pi*r*L. if you want me to check your answers I will totally do that too.

4 0

4 years ago