Evaluate x6 + y(-9)<br> When x= -2, y = 4

Which shows the integers in order.

Igoryamba

The answer A shows the integers from greatest to least

5 0

3 years ago

Read 2 more answers

CALCULUS - Find the values of in the interval (0,2pi) where the tangent line to the graph of y = sinxcosx is

Rufina [12.5K]

Answer:

$\{\frac{\pi}{4}, \frac{3\pi}{4},\frac{5\pi}{4},\frac{7\pi}{4}\}$

Step-by-step explanation:

We want to find the values between the interval (0, 2π) where the tangent line to the graph of y=sin(x)cos(x) is horizontal.

Since the tangent line is horizontal, this means that our derivative at those points are 0.

So, first, let's find the derivative of our function.

$y=\sin(x)\cos(x)$

Take the derivative of both sides with respect to x:

$\frac{d}{dx}[y]=\frac{d}{dx}[\sin(x)\cos(x)]$

We need to use the product rule:

$(uv)'=u'v+uv'$

So, differentiate:

$y'=\frac{d}{dx}[\sin(x)]\cos(x)+\sin(x)\frac{d}{dx}[\cos(x)]$

Evaluate:

$y'=(\cos(x))(\cos(x))+\sin(x)(-\sin(x))$

Simplify:

$y'=\cos^2(x)-\sin^2(x)$

Since our tangent line is horizontal, the slope is 0. So, substitute 0 for y':

$0=\cos^2(x)-\sin^2(x)$

Now, let's solve for x. First, we can use the difference of two squares to obtain:

$0=(\cos(x)-\sin(x))(\cos(x)+\sin(x))$

Zero Product Property:

$0=\cos(x)-\sin(x)\text{ or } 0=\cos(x)+\sin(x)$

Solve for each case.

Case 1:

$0=\cos(x)-\sin(x)$

Add sin(x) to both sides:

$\cos(x)=\sin(x)$

To solve this, we can use the unit circle.

Recall at what points cosine equals sine.

This only happens twice: at π/4 (45°) and at 5π/4 (225°).

At both of these points, both cosine and sine equals √2/2 and -√2/2.

And between the intervals 0 and 2π, these are the only two times that happens.

Case II:

We have:

$0=\cos(x)+\sin(x)$

Subtract sine from both sides:

$\cos(x)=-\sin(x)$

Again, we can use the unit circle. Recall when cosine is the opposite of sine.

Like the previous one, this also happens at the 45°. However, this times, it happens at 3π/4 and 7π/4.

At 3π/4, cosine is -√2/2, and sine is √2/2. If we divide by a negative, we will see that cos(x)=-sin(x).

At 7π/4, cosine is √2/2, and sine is -√2/2, thus making our equation true.

Therefore, our solution set is:

$\{\frac{\pi}{4}, \frac{3\pi}{4},\frac{5\pi}{4},\frac{7\pi}{4}\}$

And we're done!

Edit: Small Mistake :)

5 0

3 years ago

What is the slope of the line threw (-7,-2) and (-6,7)

miv72 [106K]

Answer:

9

Step-by-step explanation:

To find the slope of a line, calculate the distance between points with a ratio of vertical to horizontal distance. This is done using the formula:

$m=\frac{y_2-y_1}{x_2-x_1}$

Here the points are (-7,-2) and (-6,7). Substitute and simplify.

$m=\frac{7--2}{-6--7}=\frac{7+2}{-6+7}=\frac{9}{1}=9$

3 0

3 years ago

Mike spent half of his allowance going to the movies he washed the family car and earned 9 dollars what is his weekly allowance

EleoNora [17]

$10 I believe. Hope it helped!

8 0

4 years ago

I have a LCM and GCF homework can someone help i dont understand??

Sindrei [870]

Alright,

So LCM stands for "least common multiple"
While GCF is "greatest common factor"

Let's look at your number 1 (3&6)

3,6,9,12
6,12,18,24

Both times table has 6 in them making 6 the LCM

To find the GCF we need to know what can go into 3 equally. Since 3 is prime the greatest factor for 3 is....3. 6 goes into 3 two times so 3 is the GCF.

LCM:6
GCF:3

Lets do number 10 (40&4)

For LCM you see whats the smallest number that is in both times tables

4,8,12,16,20,24,28.......40
40,80, 160....

40 is the LCM because 40 is what's the smallest number between the two

GCF?

4 times 1 equals 4. Nothing bigger than 4 can make 4 (if your multiplying). That makes 4 automatically the GCF. :)

6 0

3 years ago

Evaluate x6 + y(-9) When x= -2, y = 4