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2 years ago

Write the function that models the relationship. z varies directly with x and inversely with y, and z = 10 when x = 5, y = 2

Mathematics

2 answers:

Mars2501 [29]2 years ago

6 0

Step-by-step explanation:

z=3227

Explanation:

the initial statement here is z∝xy2

to convert to an equation multiply by k the constant

of variation

⇒z=kxy2

to find k use the given condition

z=18 when x=6 and y=2

z=kxy2⇒k=y2zx=4×186=12

equation is ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯∣∣∣22z=12xy222∣∣∣−−−−−−−−−−−−−

when x=8 and y=9

z=12×881=3227

fiasKO [112]2 years ago

6 0

Answer:

z = $\frac{4x}{y}$

Step-by-step explanation:

Given z varies directly with x and inversely with y then the equation relating them is

z = k × $\frac{x}{y}$ ← k is the constant of variation

To find k use the condition z = 10 when x = 5 and y = 2, then

10 = k × $\frac{5}{2}$ ( multiply both sides by 2 to clear the fraction

20 = 5k ( divide both sides by 5 )

4 = k

z = $\frac{4x}{y}$ ← equation of variation

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Help Dana find the sum 346 421 152

lara [203]

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3 4 6

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Therefore, 13a) No.

There is no regrouped tens to add, so we would not able to regroup the ones place.

Therefore, 13b) No.

We regroup the tens place because the sum of the digits in the ones place is upto to 10.

And 13c) Yes.

We add the regrouped hundred as we regrouped the ones place.

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2 years ago

1. Let f(x, y) be a differentiable function in the variables x and y. Let r and θ the polar coordinates,and set g(r, θ) = f(r co

Olenka [21]

Answer:

$g_{r}(\sqrt{2},\frac{\pi}{4})=\frac{\sqrt{2}}{2}\\$

Step-by-step explanation:

First, notice that:

$g(\sqrt{2},\frac{\pi}{4})=f(\sqrt{2}cos(\frac{\pi}{4}),\sqrt{2}sin(\frac{\pi}{4}))\\$

$g(\sqrt{2},\frac{\pi}{4})=f(\sqrt{2}(\frac{1}{\sqrt{2}}),\sqrt{2}(\frac{1}{\sqrt{2}}))\\$

$g(\sqrt{2},\frac{\pi}{4})=f(1,1)\\$

We proceed to use the chain rule to find $g_{r}(\sqrt{2},\frac{\pi}{4})$ using the fact that $X(r,\theta)=rcos(\theta)\ and\ Y(r,\theta)=rsin(\theta)$ to find their derivatives:

$g_{r}(r,\theta)=f_{r}(rcos(\theta),rsin(\theta))=f_{x}( rcos(\theta),rsin(\theta))\frac{\delta x}{\delta r}(r,\theta)+f_{y}(rcos(\theta),rsin(\theta))\frac{\delta y}{\delta r}(r,\theta)\\$

Because we know $X(r,\theta)=rcos(\theta)\ and\ Y(r,\theta)=rsin(\theta)$ then:

$\frac{\delta x}{\delta r}=cos(\theta)\ and\ \frac{\delta y}{\delta r}=sin(\theta)$

We substitute in what we had:

$g_{r}(r,\theta)=f_{x}( rcos(\theta),rsin(\theta))cos(\theta)+f_{y}(rcos(\theta),rsin(\theta))sin(\theta)$

Now we put in the values $r=\sqrt{2}\ and\ \theta=\frac{\pi}{4}$ in the formula:

$g_{r}(\sqrt{2},\frac{\pi}{4})=f_{r}(1,1)=f_{x}(1,1)cos(\frac{\pi}{4})+f_{y}(1,1)sin(\frac{\pi}{4})$

Because of what we supposed:

$g_{r}(\sqrt{2},\frac{\pi}{4})=f_{r}(1,1)=-2cos(\frac{\pi}{4})+3sin(\frac{\pi}{4})$

And we operate to discover that:

$g_{r}(\sqrt{2},\frac{\pi}{4})=-2\frac{\sqrt{2}}{2}+3\frac{\sqrt{2}}{2}$

$g_{r}(\sqrt{2},\frac{\pi}{4})=\frac{\sqrt{2}}{2}$

and this will be our answer

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2 years ago

A) give stating reasons five other angles each equal to x b) prove that AECF is a parallelogram

Gennadij [26K]

Simple Proof:

a) In the image, we know that ABCD is a parallelogram and that means opposite angel measures should be the same. We know that angel DCB is made up by angel 1 and 2, and angel DAB and DCB are equal and angel DAB is made up by angel 1 and x. So now we can conclude that angel x is equal to angel 2.

b) According to the definitions of a parallelogram, opposite angel measures have to be the same, while AECF have angle 1 to angel 1 and angel 2 to angel 1. We can conclude that AECF is NOT a parallelogram. (Sorry, you didn't give me the full question so some information remains unclear. )

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2 years ago

Poloma believes that the equation of the line of best fit for the following scatterplot is y=5/6x-31/6. Which statement best sum

kumpel [21]

Answer:

Poloma’s equation has a positive slope, but the scatter-plot has a negative correlation.

Step-by-step explanation:

The scatter-plot is as shown in the attached figure.

As shown in the figure, the scatter-plot has a negative correlation.

And the equation of Poloma is y = 5/6x - 31/6

Where the slope of the line = 5/6 and y-intercept = -31/6

According to the previous information, the true statement is: