The sum of four and twelve is??

Express each rate as a unit rate. 720 miles traveled on 60 gallons of gasoline=

Brut [27]

720 miles traveled on 60 gallons of gasoline.
Express this on its Unit Rate.
To get the answer, we need to divide 720 miles by 60 gallons of gasoline
=> 720 / 60 = 12 miles /gallons
Thus, in every 1 gallon of gasoline, you can travel 12 miles.
So, the expression would be like this:
720 miles / 60 gallons = 12 miles / gallon
Let’s check our answer
=> 12 miles x 60 gallons = 720 miles.
Thus, we got the correct answer.

7 0

3 years ago

How to find the derivative of cos^2x? i seem to be confused.

slamgirl [31]

If you're using the app, try seeing this answer through your browser: brainly.com/question/2927231

————————

You can actually use either the product rule or the chain rule for this one. Observe:

• Method I:

y = cos² x

y = cos x · cos x

Differentiate it by applying the product rule:

$\mathsf{\dfrac{dy}{dx}=\dfrac{d}{dx}(cos\,x\cdot cos\,x)}\\\\\\
\mathsf{\dfrac{dy}{dx}=\dfrac{d}{dx}(cos\,x)\cdot cos\,x+cos\,x\cdot \dfrac{d}{dx}(cos\,x)}$

The derivative of cos x is – sin x. So you have

$\mathsf{\dfrac{dy}{dx}=(-sin\,x)\cdot cos\,x+cos\,x\cdot (-sin\,x)}\\\\\\
\mathsf{\dfrac{dy}{dx}=-sin\,x\cdot cos\,x-cos\,x\cdot sin\,x}$

$\therefore~~\boxed{\begin{array}{c}\mathsf{\dfrac{dy}{dx}=-2\,sin\,x\cdot cos\,x}\end{array}}\qquad\quad\checkmark$

—————

• Method II:

You can also treat y as a composite function:

$\left\{\!
\begin{array}{l}
\mathsf{y=u^2}\\\\
\mathsf{u=cos\,x}
\end{array}
\right.$

and then, differentiate y by applying the chain rule:

$\mathsf{\dfrac{dy}{dx}=\dfrac{dy}{du}\cdot \dfrac{du}{dx}}\\\\\\
\mathsf{\dfrac{dy}{dx}=\dfrac{d}{du}(u^2)\cdot \dfrac{d}{dx}(cos\,x)}$

For that first derivative with respect to u, just use the power rule, then you have

$\mathsf{\dfrac{dy}{dx}=2u^{2-1}\cdot \dfrac{d}{dx}(cos\,x)}\\\\\\
\mathsf{\dfrac{dy}{dx}=2u\cdot (-sin\,x)\qquad\quad (but~~u=cos\,x)}\\\\\\
\mathsf{\dfrac{dy}{dx}=2\,cos\,x\cdot (-sin\,x)}$

and then you get the same answer:

$\therefore~~\boxed{\begin{array}{c}\mathsf{\dfrac{dy}{dx}=-2\,sin\,x\cdot cos\,x}\end{array}}\qquad\quad\checkmark$

I hope this helps. =)

Tags: <em>derivative chain rule product rule composite function trigonometric trig squared cosine cos differential integral calculus</em>

3 0

3 years ago

If you were to use the substitution method to solve the following system, choose the new

mestny [16]

Answer:

23x = -115

Step-by-step explanation:

In the substitution method, you must solve for 1 variable in 1 equation to replace it in the other equation. For the system:

2x - 7y = 4

3x + y = -17

Solving for y in the second equation:

y = -17 - 3x

Replacing y in the first equation:

2x - 7(-17 - 3x) = 4

2x + 119 + 21x = 4

23x = -115

This is the new equation after use the substitution method.

5 0

3 years ago

Two persons start running simultaneously from a certain point, one towards south and another towards east. After 2 hours, the di

Volgvan

The Pythagorean theorem is sometimes known as Pythagoras' theorem. The speed of the faster person is 40 kmph.

<h3>What is Pythagoras' theorem?</h3>

The Pythagorean theorem, sometimes known as Pythagoras' theorem, is a basic relationship between the three sides of a right triangle in Euclidean geometry. The size of the square whose side is the hypotenuse is equal to the sum of the areas of the squares on the other two sides, according to this rule.

Let the speed of one person be represented by x, then the speed of the other person, if the speed of the second person is 75% of the first.

Speed of first-person = x
Speed of second-person = 75% of Speed of first-person = 0.75x

Now, the distance covered by two persons in 2 hours is,

Distance covered by the first-person = x × 2 = 2x
Distance covered by the second-person = 0.75x × 2 = 1.5x

Since one person runs towards the south and another towards the east. Therefore, will form a 90° angle between their directions.

Now, the distance between the two after two hours is 100 km, therefore, we can write,

(2x)² + (1.5x)² = 100²

4x² + 2.25x² = 10000

6.25x² = 10000

x² = 10000/6.25

x² = 1600

x = √1600

x = 40

Hence, the speed of the faster person is 40 kmph.

Learn more about Pythagoras' Theorem here:

brainly.com/question/14461977

#SPJ4

6 0

1 year ago

Can someone help me with this? ( solving angle measures)

raketka [301]

Answer:

38°

Step-by-step explanation:

Complementary means that they add up to 90
So then to find the measure of angle 2, subtract the measure of angle 1 from 90.

90-52=<u>38</u>

5 0

3 years ago

Read 2 more answers