The scatter plot shows the number of tickets sold and the price of the tickets.

Can somone please help me? I need help with 7 different problems!! and fasttttt

kramer

What problems are they??

8 0

3 years ago

How to know if a function is periodic without graphing it ?

zhenek [66]

A function $f(t)$ is periodic if there is some constant $k$ such that $f(t+k)=f(k)$ for all $t$ in the domain of $f(t)$ . Then $k$ is the "period" of $f(t)$ .

Example:

If $f(x)=\sin x$ , then we have $\sin(x+2\pi)=\sin x\cos2\pi+\cos x\sin2\pi=\sin x$ , and so $\sin x$ is periodic with period $2\pi$ .

It gets a bit more complicated for a function like yours. We're looking for $k$ such that

$\pi\sin\left(\dfrac\pi2(t+k)\right)+1.8\cos\left(\dfrac{7\pi}5(t+k)\right)=\pi\sin\dfrac{\pi t}2+1.8\cos\dfrac{7\pi t}5$

Expanding on the left, you have

$\pi\sin\dfrac{\pi t}2\cos\dfrac{k\pi}2+\pi\cos\dfrac{\pi t}2\sin\dfrac{k\pi}2$

and

$1.8\cos\dfrac{7\pi t}5\cos\dfrac{7k\pi}5-1.8\sin\dfrac{7\pi t}5\sin\dfrac{7k\pi}5$

It follows that the following must be satisfied:

$\begin{cases}\cos\dfrac{k\pi}2=1\\\\\sin\dfrac{k\pi}2=0\\\\\cos\dfrac{7k\pi}5=1\\\\\sin\dfrac{7k\pi}5=0\end{cases}$

The first two equations are satisfied whenever $k\in\{0,\pm4,\pm8,\ldots\}$ , or more generally, when $k=4n$ and $n\in\mathbb Z$ (i.e. any multiple of 4).

The second two are satisfied whenever $k\in\left\{0,\pm\dfrac{10}7,\pm\dfrac{20}7,\ldots\right\}$ , and more generally when $k=\dfrac{10n}7$ with $n\in\mathbb Z$ (any multiple of 10/7).

It then follows that all four equations will be satisfied whenever the two sets above intersect. This happens when $k$ is any common multiple of 4 and 10/7. The least positive one would be 20, which means the period for your function is 20.

Let's verify:

$\sin\left(\dfrac\pi2(t+20)\right)=\sin\dfrac{\pi t}2\underbrace{\cos10\pi}_1+\cos\dfrac{\pi t}2\underbrace{\sin10\pi}_0=\sin\dfrac{\pi t}2$

$\cos\left(\dfrac{7\pi}5(t+20)\right)=\cos\dfrac{7\pi t}5\underbrace{\cos28\pi}_1-\sin\dfrac{7\pi t}5\underbrace{\sin28\pi}_0=\cos\dfrac{7\pi t}5$

More generally, it can be shown that

$f(t)=\displaystyle\sum_{i=1}^n(a_i\sin(b_it)+c_i\cos(d_it))$

is periodic with period $\mbox{lcm}(b_1,\ldots,b_n,d_1,\ldots,d_n)$ .

4 0

3 years ago

Your college roommate receives a pay raise at her part-time job from $9 to $11 per hour. She used to work 25 hours per week, but

Fynjy0 [20]

Answer:

d. backward sloping.

Step-by-step explanation:

The roommate receives a pay raise at her part-time job from $9 to $11 per hour and now decides to work 20 hours per week instead to 25 hours per week.

We can see that her rate is decreasing, so her labor supply curve is backward sloping or also called backward bending.

It is mostly found that worker's labor supply curve, slopes upward when they get lower wages and the curve bends backward when they get higher wages because a worker tends to work less when his wage rate rises.

6 0

3 years ago

Question:

12345 [234]

Answer:

A. Area in square inches = 1760 square inches

B. Area in square feet = 12.2 square feet

C. 1 square inch = $\frac{1}{144}$ feet

Step-by-step explanation:

Given,

Length of the rectangle (l) = 55 inches

Breath of the rectangle (b) = 32 inches

A. Area of the rectangle = length × breath

⇒ 55 × 32

⇒ 1760 square inches

Area in square inches = 1760 square inches

B. 1 foot = 12 inches

1 inch = $\frac{1}{12}$ feet

1 square inch = $\frac{1}{144}$ feet

∴ 1760 square inches = $\frac{1760}{144}$ feet

⇒ 12.2222 square feet

Area in square feet = 12.2 square feet

C. 1 square inch = $\frac{1}{144}$ feet

8 0

3 years ago

Please help hurry! ty

MAXImum [283]

Answer:

....

Step-by-step explanation:

3 0

3 years ago