How would you show a of rate changeof 15 feet per second on a graph

△BCD is a right triangle. The length of the hypotenuse is 19 centimeters. The length of one of the legs is 13 centimeters.

zheka24 [161]

here we can use Pythogoras' theorem.
in right angled triangles the square of the hypotenuse is equal to the sum of the squares of the other 2 sides.
hypotenuse is 19 cm. One side is 13 cm and we need to find the length of the third side.

19² = 13² + X²
X - length of the third side

361 = 169 + X²
X² = 361 - 169

X² = 192

X = 13.85 the length of third side rounded off to the nearest tenth is 13.9 cm

3 0

2 years ago

A circle has the order pairs (-1, 2) (0, 1) (-2, -1) what is the equation . Show your work.

olga55 [171]

We know that:

$(x-a)^2+(y-b)^2=r^2$

is an equation of a circle.

When we substitute x and y (from the pairs we have), we'll get a system of equations:

$\begin{cases}(-1-a)^2+(2-b)^2=r^2\\(0-a)^2+(1-b)^2=r^2\\(-2-a)^2+(-1-b)^2=r^2\end{cases}$

and all we have to do is solve it for a, b and r.

There will be:

$\begin{cases}(-1-a)^2+(2-b)^2=r^2\\(0-a)^2+(1-b)^2=r^2\\(-2-a)^2+(-1-b)^2=r^2\end{cases}\\\\\\
\begin{cases}1+2a+a^2+4-4b+b^2=r^2\\a^2+1-2b+b^2=r^2\\4+4a+a^2+1+2b+b^2=r^2\end{cases}\\\\\\
\begin{cases}a^2+b^2+2a-4b+5=r^2\\a^2+b^2-2b+1=r^2\\a^2+b^2+4a+2b+5=r^2\end{cases}\\\\\\
$

From equations (II) and (III) we have:

$\begin{cases}a^2+b^2-2b+1=r^2\\a^2+b^2+4a+2b+5=r^2\end{cases}\\--------------(-)\\\\a^2+b^2-2b+1-a^2-b^2-4a-2b-5=r^2-r^2\\\\-4a-4b-4=0\qquad|:(-4)\\\\\boxed{-a-b-1=0}$

and from (I) and (II):

$\begin{cases}a^2+b^2+2a-4b+5=r^2\\a^2+b^2-2b+1=r^2\end{cases}\\--------------(-)\\\\a^2+b^2+2a-4b+5-a^2-b^2+2b-1=r^2-r^2\\\\2a-2b+4=0\qquad|:2\\\\\boxed{a-b+2=0}$

Now we can easly calculate a and b:

$\begin{cases}-a-b-1=0\\a-b+2=0\end{cases}\\--------(+)\\\\-a-b-1+a-b+2=0+0\\\\-2b+1=0\\\\-2b=-1\qquad|:(-2)\\\\\boxed{b=\frac{1}{2}}\\\\\\\\a-b+2=0\\\\\\a-\dfrac{1}{2}+2=0\\\\\\a+\dfrac{3}{2}=0\\\\\\\boxed{a=-\frac{3}{2}}$

Finally we calculate $r^2$ :

$a^2+b^2-2b+1=r^2\\\\\\\left(-\dfrac{3}{2}\right)^2+\left(\dfrac{1}{2}\right)^2-2\cdot\dfrac{1}{2}+1=r^2\\\\\\\dfrac{9}{4}+\dfrac{1}{4}-1+1=r^2\\\\\\\dfrac{10}{4}=r^2\\\\\\\boxed{r^2=\frac{5}{2}}$

And the equation of the circle is:

$(x-a)^2+(y-b)^2=r^2\\\\\\\left(x-\left(-\dfrac{3}{2}\right)\right)^2+\left(y-\dfrac{1}{2}\right)^2=\dfrac{5}{2}\\\\\\\boxed{\left(x+\dfrac{3}{2}\right)^2+\left(y-\dfrac{1}{2}\right)^2=\dfrac{5}{2}}$

7 0

3 years ago

Vlad spent 20 minutes on his history homework and then completely solved x math problems that each took 2 minutes to complete. W

Veronika [31]

To solve you first need to pick out the most important information,
~Spent 20 minutes
~Each prob takes 2 minutes
Lets have y be the total time spent, and x the number of probs
(y/2) = x
Hope this helped!! ^-^

6 0

3 years ago

Read 2 more answers

How many unit cubes will fit in the rectangular prism? A) 9 B) 36 C) 40 D) 45

antiseptic1488 [7]

Answer:

D) 45

Step-by-step explanation:

5 x 3 x 3 = 45

8 0

2 years ago

What is the unit rate for 14lb for 2.99

Maurinko [17]

How to find the unit of rate. Well, in this case finding the unit rate would be pretty simple. All you have to do is take 14Ib and 2.99 and divide them the equation will look like this 14÷2.99=4.682274247491638796 so your answer (I think please correct me if I'm wrong and I am sooo sorry if I'm wrong) would be 4.68 or 4.6

4 0

2 years ago