Help! does anyone know the answer to this

Find the length of the curve. R(t) = cos(8t) i + sin(8t) j + 8 ln cos t k, 0 ≤ t ≤ π/4

arsen [322]

we are given

$R(t)=cos(8t)i+sin(8t)j+8ln(cos(t))k$

now, we can find x , y and z components

$x=cos(8t),y=sin(8t),z=8ln(cos(t))$

Arc length calculation:

we can use formula

$L=\int\limits^a_b {\sqrt{(x')^2+(y')^2+(z')^2} } \, dt$

$x'=-8sin(8t),y=8cos(8t),z=-8tan(t)$

now, we can plug these values

$L=\int _0^{\frac{\pi }{4}}\sqrt{(-8sin(8t))^2+(8cos(8t))^2+(-8tan(t))^2} dt$

now, we can simplify it

$L=\int _0^{\frac{\pi }{4}}\sqrt{64+64tan^2(t)} dt$

$L=\int _0^{\frac{\pi }{4}}8\sqrt{1+tan^2(t)} dt$

$L=\int _0^{\frac{\pi }{4}}8\sqrt{sec^2(t)} dt$

$L=\int _0^{\frac{\pi }{4}}8sec(t) dt$

now, we can solve integral

$\int \:8\sec \left(t\right)dt$

$=8\ln \left|\tan \left(t\right)+\sec \left(t\right)\right|$

now, we can plug bounds

and we get

$=8\ln \left(\sqrt{2}+1\right)-0$

so,

$L=8\ln \left(1+\sqrt{2}\right)$ ..............Answer

5 0

3 years ago

Which expression is equivalent to |a|≤5 ?

sladkih [1.3K]

Answer:

I think its the first one but not 100 % sure

Step-by-step explanation:

8 0

3 years ago

Read 2 more answers

To make a solution for an experiment, Gunther needs to add 40 g of a solute to 100 g of water. When making the

Tems11 [23]

Answer:

B. Heat the solution, dissolve the solute, and let the solution cool verifying nothing settled out.

Step-by-step explanation:

4 0

3 years ago

Read 2 more answers

Ellie invested $13,000 in an account paying an interest rate of 8.25% compounded

Mila [183]

Answer:

Rate 1: 8

4

1

%=8+1/4=

8.25

%

→

0.0825

8.25%→0.0825

Rate 2:

8

1

2

%

=

8

+

1

/

2

=

Rate 2: 8

2

1

%=8+1/2=

8.5

%

→

0.085

8.5%→0.085

Calculate Final Amount for Ellie

‾

Calculate Final Amount for Ellie

Compounded Continuously:

A

=

P

e

r

t

A=Pe

rt

P

=

13000

r

=

0.0825

t

=

18

P=13000r=0.0825t=18

Given values

A

=

13000

e

0.0825

(

18

)

A=13000e

0.0825(18)

Plug in

A

=

13000

e

1.485

A=13000e

1.485

Multiply

A

=

57394.5504

A=57394.5504

Use calculator (with e button)

Calculate Final Amount for Daniel

‾

Calculate Final Amount for Daniel

Compounded Daily:

A

=

P

(

1

+

r

n

)

n

t

A=P(1+

n

r

)

nt

Compound interest formula

P

=

13000

r

=

0.085

t

=

18

n

=

365

P=13000r=0.085t=18n=365

Given values

A

=

13000

(

1

+

0.085

365

)

365

(

18

)

A=13000(1+

365

0.085

)

365(18)

Plug in values

A

=

13000

(

1.0002329

)

6570

A=13000(1.0002329)

6570

Simplify

A

=

60025.6058

A=60025.6058

Use calculator

How much more money Daniel has:

60025.6058

Rate 1: 8

4

1

%=8+1/4=

8.25

%

→

0.0825

8.25%→0.0825

Rate 2:

8

1

2

%

=

8

+

1

/

2

=

Rate 2: 8

2

1

%=8+1/2=

8.5

%

→

0.085

8.5%→0.085

Calculate Final Amount for Ellie

‾

Calculate Final Amount for Ellie

Compounded Continuously:

A

=

P

e

r

t

A=Pe

rt

P

=

13000

r

=

0.0825

t

=

18

P=13000r=0.0825t=18

Given values

A

=

13000

e

0.0825

(

18

)

A=13000e

0.0825(18)

Plug in

A

=

13000

e

1.485

A=13000e

1.485

Multiply

A

=

57394.5504

A=57394.5504

Use calculator (with e button)

Calculate Final Amount for Daniel

‾

Calculate Final Amount for Daniel

Compounded Daily:

A

=

P

(

1

+

r

n

)

n

t

A=P(1+

n

r

)

nt

Compound interest formula

P

=

13000

r

=

0.085

t

=

18

n

=

365

P=13000r=0.085t=18n=365

Given values

A

=

13000

(

1

+

0.085

365

)

365

(

18

)

A=13000(1+

365

0.085

)

365(18)

Plug in values

A

=

13000

(

1.0002329

)

6570

A=13000(1.0002329)

6570

Simplify

A

=

60025.6058

A=60025.6058

Use calculator

How much more money Daniel has:

60025.6058

−

57394.5504

60025.6058−57394.5504

2631.0554

$

2631

$2631

Round to the nearest dollar−

57394.5504

60025.6058−57394.5504

2631.0554

$

2631

$2631

Round to the nearest dollar

Step-by-step explanation:

3 0

3 years ago

How do you solve this

lara [203]

Answer would be

p
--------------------
q^2 r^3

4 0

3 years ago