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1 year ago

8

Tap A can fill 4 pails in 55 seconds.

1 answer:

rewona [7]1 year ago

7 0

Answer:

Below in bold.

Step-by-step explanation:

Work in times to fill 1 pail:-

tap A takes 55/4 seconds

tap B takes 50/3 seconds

Let time to fill one pail be x when filling together, then:

3/50 + 4/55 = 1/x

165x + 200x = 55*50

x = 2750 /(365) = 7.5342 seconds

To fill 16 pails it takes 7.5342* 16

= 120.55 seconds

= 2 minutes 1 second to the nearest second..

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B = 23a + 1<br> b = -13a + 7

ohaa [14]

The answer is the question

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3 years ago

Find the exact value of the expression.<br> tan( sin−1 (2/3)− cos−1(1/7))

Sonja [21]

Answer:

$\tan(a-b)=\frac{2\sqrt{5}-20\sqrt{3}}{5+8\sqrt{15}}$

Step-by-step explanation:

I'm going to use the following identity to help with the difference inside the tangent function there:

$\tan(a-b)=\frac{\tan(a)-\tan(b)}{1+\tan(a)\tan(b)}$

Let $a=\sin^{-1}(\frac{2}{3})$ .

With some restriction on $a$ this means:

$\sin(a)=\frac{2}{3}$

We need to find $\tan(a)$ .

$\sin^2(a)+\cos^2(a)=1$ is a Pythagorean Identity I will use to find the cosine value and then I will use that the tangent function is the ratio of sine to cosine.

$(\frac{2}{3})^2+\cos^2(a)=1$

$\frac{4}{9}+\cos^2(a)=1$

Subtract 4/9 on both sides:

$\cos^2(a)=\frac{5}{9}$

Take the square root of both sides:

$\cos(a)=\pm \sqrt{\frac{5}{9}}$

$\cos(a)=\pm \frac{\sqrt{5}}{3}$

The cosine value is positive because $a$ is a number between $-\frac{\pi}{2}$ and $\frac{\pi}{2}$ because that is the restriction on sine inverse.

So we have $\cos(a)=\frac{\sqrt{5}}{3}$ .

This means that $\tan(a)=\frac{\frac{2}{3}}{\frac{\sqrt{5}}{3}}$ .

Multiplying numerator and denominator by 3 gives us:

$\tan(a)=\frac{2}{\sqrt{5}}$

Rationalizing the denominator by multiplying top and bottom by square root of 5 gives us:

$\tan(a)=\frac{2\sqrt{5}}{5}$

Let's continue on to letting $b=\cos^{-1}(\frac{1}{7})$ .

Let's go ahead and say what the restrictions on $b$ are.

$b$ is a number in between 0 and $\pi$ .

So anyways $b=\cos^{-1}(\frac{1}{7})$ implies $\cos(b)=\frac{1}{7}$ .

Let's use the Pythagorean Identity again I mentioned from before to find the sine value of $b$ .

$\cos^2(b)+\sin^2(b)=1$

$(\frac{1}{7})^2+\sin^2(b)=1$

$\frac{1}{49}+\sin^2(b)=1$

Subtract 1/49 on both sides:

$\sin^2(b)=\frac{48}{49}$

Take the square root of both sides:

$\sin(b)=\pm \sqrt{\frac{48}{49}$

$\sin(b)=\pm \frac{\sqrt{48}}{7}$

$\sin(b)=\pm \frac{\sqrt{16}\sqrt{3}}{7}$

$\sin(b)=\pm \frac{4\sqrt{3}}{7}$

So since $b$ is a number between $0$ and $\pi$ , then sine of this value is positive.

This implies:

$\sin(b)=\frac{4\sqrt{3}}{7}$

So $\tan(b)=\frac{\sin(b)}{\cos(b)}=\frac{\frac{4\sqrt{3}}{7}}{\frac{1}{7}}$ .

Multiplying both top and bottom by 7 gives:

$\frac{4\sqrt{3}}{1}= 4\sqrt{3}$ .

Let's put everything back into the first mentioned identity.

$\tan(a-b)=\frac{\tan(a)-\tan(b)}{1+\tan(a)\tan(b)}$

$\tan(a-b)=\frac{\frac{2\sqrt{5}}{5}-4\sqrt{3}}{1+\frac{2\sqrt{5}}{5}\cdot 4\sqrt{3}}$

Let's clear the mini-fractions by multiply top and bottom by the least common multiple of the denominators of these mini-fractions. That is, we are multiplying top and bottom by 5:

$\tan(a-b)=\frac{2 \sqrt{5}-20\sqrt{3}}{5+2\sqrt{5}\cdot 4\sqrt{3}}$

$\tan(a-b)=\frac{2\sqrt{5}-20\sqrt{3}}{5+8\sqrt{15}}$

4 0

2 years ago

Which expression is the completely factored form of x6−64y3 ?

ss7ja [257]

We are given this

$x^6 -64y^3$

write it as the difference of cubes

$(x^2)^3 -(4y)^3$

use the formula for the difference of cubes

$(x^2-4y) ((x^2)^2+x^2*4y+(4y)^2)$

Now use the formula for the difference of squares as $4y = (2\sqrt{y} )^2$

$(x-2\sqrt{y}) (x+2\sqrt{y}) (x^4+4x^2y+16y^2)$

7 0

3 years ago

Read 2 more answers

Make x the subject of the formula y= b/ax

neonofarm [45]

Answer:

x=b/(ay)

Step-by-step explanation:

To make x the subject of the formula, we basically have to isolate the x.

To do this we first multiply both sides by x.

xy=b/a

Now, to isolate the x, we simply divide by y,

x=b/(ay)

So x=b/(ay) is our answer

8 0

3 years ago

Describe all of the transformations occurring as the parent function f(x) = x^3 is transformed into g(x) = -0.5(3(x+4))^3 -8

hodyreva [135]

Step-by-step explanation:

The translations of the typical functions are

$y = a(bx + c) + d$

Where a is the vertical translation,

If a is greater than 1 or less than -1, we have a vertical stretch

If a is between -1 and 1 , we have a vertical compressions or shrink.

If a is negative, we have a negative reflection across the x axis.

If b is greater than 1 or less than -1, we have a horizontal compression or shrink

If b is between -1 and 1, we have a horizontal stretch

If b is negative, we have a reflection about the y axis,

If c is negative, we have a translation to the right c units

If c is positive, we have a translation to the left c units

If d is positive, we have a translation upward d units

If d is negative, we have a translation downward d units.

Here in this problem, our parent function is x^3.

So I would do the following transformations.

Reflect about the x axis
Vertical Shrink by a factor of 1/2
Horizontal Shrink by a factor of 3
Shift to the left 4 units
Shift downward 8 units.

4 0

1 year ago