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3 years ago

•Plz help it’s due tomorrow, the work is abt equations•

Mathematics

2 answers:

Artemon [7]3 years ago

4 0

15 = C (y=4x-3)
16= F (y-1=2(x-3)
17= B

sertanlavr [38]3 years ago

3 0

Question #15:

Slope-intercept form: y = mx + b

(m is the slope, b is the y-intercept or the y value when x = 0 --> (0, y) or the point where the line crosses through the y-axis)

You know:

m = 4

b = -3 So substitute/plug it into the equation

y = mx + b

y = (4)x + (-3)

y = 4x - 3 Your answer is C

Question #16:

Point-slope form: y - y₁ = m(x - x₁)

(m is the slope, (x₁ , y₁) is the point you are given)

You know:

m = 2

(x₁ , y₁) = (3, 1) So substitute/plug it into the equation

y - y₁ = m(x - x₁)

y - (1) = 2(x - (3))

y - 1 = 2(x - 3) Your answer is F

Questions #17:

Yoga lessons cost $5 per lesson if Kylie enrolls in the health club for a fee of $120 per year. Which equation represents the yearly cost C of l yoga lessons?

C = the total cost of a year

l = the number of yoga lessons

C = 5l + 120

(the total cost of a year = $5 per lesson(l) plus a fee of $120 per year, so you pay a fee of $120 once a year)

Your answer is B

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If l=10, b=5, h=2, find the values of 2h(l+b)

Eddi Din [679]

Answer:

Step-by-step explanation:

given:

l = 10

b = 5

h = 2

to find:

2h(l + b)

substitute the given values of l , b and h

=2*2(10 + 5)

=4*15

=60

3 0

3 years ago

Read 2 more answers

Which digit in the following number is the one that determines its precision? 183.6

mote1985 [20]

precision is after the decimal point.

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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

Carlos has 2,175 marbles in his collection . Emily has 1833 marbles in her collection . Carlos says that he has about 1,000 more

kenny6666 [7]

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3 years ago

PLEASE HELP ME:complete the chart to compare the distance each ballon moved from the dasged line

AURORKA [14]

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3 years ago