F(x) = <br> sin 4x/2x<br> x-intercepts?

Use chain rule to find dw/dt w=ln(x^2 + y^2 + z^2)^(1/2) , x=sint, y=cost, z=tant

son4ous [18]

The chain rule states that

$\dfrac{\mathrm dw}{\mathrm dt}=\dfrac{\partial w}{\partial x}\dfrac{\mathrm dx}{\mathrm dt}+\dfrac{\partial w}{\partial y}\dfrac{\mathrm dy}{\mathrm dt}+\dfrac{\partial w}{\partial z}\dfrac{\mathrm dz}{\mathrm dt}$

Since $\ln(x^2+y^2+z^2)^{1/2}=\dfrac12\ln(x^2+y^2+z^2)$ , you have

$\dfrac{\partial w}{\partial x}=\dfrac x{x^2+y^2+z^2}$
$\dfrac{\partial w}{\partial x}=\dfrac y{x^2+y^2+z^2}$
$\dfrac{\partial w}{\partial z}=\dfrac z{x^2+y^2+z^2}$

and

$\dfrac{\mathrm dx}{\mathrm dt}=\cos t$
$\dfrac{\mathrm dy}{\mathrm dt}=-\sin t$
$\dfrac{\mathrm dz}{\mathrm dt}=\sec^2t$

Also, since $x^2+y^2+z^2=\sin^2t+\cos^2t+\tan^2t=1+\tan^2t=\sec^2t$ , the derivative is

$\dfrac{\mathrm dw}{\mathrm dt}=\dfrac{\sin t\cos t}{\sec^2t}-\dfrac{\sin t\cos t}{\sec^2t}+\dfrac{\tan t\sec^2t}{\sec^2t}$
$\dfrac{\mathrm dw}{\mathrm dt}=\tan t$

4 0

2 years ago

Gianna is going to throw a ball from the top floor of her middle school. When she throws the hall from 48 feet above the ground,

vazorg [7]

Answer:

So, the times the ball will be 48 feet above the ground are t = 0 and t = 2.

Step-by-step explanation:

The height h of the ball is modeled by the following equation

$h(t)=-16t^2+32t+48$

The problem want you to find the times the ball will be 48 feet above the ground.

It is going to be when:

$h(t) = 48$

$h(t)=-16t^{2}+32t+48$

$48=-16t^{2}+32t+48$

$0=-16t^{2}+32t+48 - 48$

$16t^{2} - 32t = 0$

We can simplify by 16t. So

$16t(t-2)= 0$

It means that

16t = 0

t = 0

or

t - 2 = 0

t = 2

So, the times the ball will be 48 feet above the ground are t = 0 and t = 2.

6 0

3 years ago

Simplify 6x+(- 9)-9(5x+5)+x

Hatshy [7]

Answer:

Step-by-step explanation:

I've already answered this question.

4 0

3 years ago

Read 2 more answers

Can someone please help me on this one?

tensa zangetsu [6.8K]

8 is the correct answer

7 0

3 years ago

Read 2 more answers

The quotient of a number and 3 decreased by 121 is -164. Select the solution to the sentence shown.

docker41 [41]

Its algebra. The original equation is $\frac{x}{3} -121 = -164$

To solve for a variable, we reverse the order of operations, beginning with addition/subtraction, and then multiplication/division. To remove a number from one side, we must do the opposite to the other side. In this case, to get rid of the -121 we must add 121 to the -164. This gives us -43. Then, to get the x by itself, we must multiply the other side by 3. -43*3=129

When we are doing the opposite of an operation to the other side, we are really reversing the operation and, to keep both sides equal, we must do whatever we have done to one side to the other side. So when we have -121, we add 121 as it equals 0, therefore it is gone. Since a equation must be balanced, we have to do what we did to the other side (adding 121).

6 0

3 years ago

F(x) = sin 4x/2x x-intercepts?