X - 37 ≤ -1 13/14 solve

Find T, N, and kappa for the plane curve Bold r left parenthesis t right parenthesis equalsleft parenthesis 7 Bold cos t plus

pickupchik [31]

Answer:

Step-by-step explanation:

r(t) = (7 cost + 7t sin t)i + (7 sin t - 7t cos t)j

$\frac{d \bar r t}{dt} =(7\frac{d}{dt}\cos t + 7\frac{d}{dt} (t \sin t)i+(7\frac{d}{dt} \sin t-7\frac{d}{dt} t \cos t)j$

$=(7(-\sin t)+7(1* \sin t+t \cos t))i+(7 \cost -7(1*\cos t - t \sin t))j\\\\=7((-\sin t+\sin t+t \cos t)i+(\cos t-\cos t+t \sin t)j)\\\\=7((t\cos t)i+(t\sin t)j)$

$\bar r'(t)=\frac{d \bar r t}{dt} =(7t\cos t)i+(7t\sin t)j---(1)\\\\11\bar r(t)=\sqrt{(7t\cos t)^2+(7t\sin t)^2}\\\\=\sqrt{49t^2(\cos^2t+\sin^2 t)} \\\\=7t$

$\bar T (t)=\frac{\bar r'(t)}{11\bar r(t)11} =\frac{(7t\cos t)i+(7t\sin t)j}{7t} \\\\\barT(t)=(\cos t)i+(\sin t)j$

$\bar T'(t)=\frac{d}{dt} (\cos t)i+\frac{d}{dt} (\sin t) j\\\\\bar T'(t)=(-\sin t)i+(\cos t)j---(2)\\\\11\bar T'(t)=\sqrt{(-\sin t)^2+(\cos t)^2} \\\\=\sqrt{\sin^2t+\cos^2t} \\\\=1$

$\bar N(t)=\bar T'(t)=\frac{(-\sin t)i+(\cos t)j}{(1)} \\\\ \large \boxed {\bar N(t)=(-\sin t)i+(\cos t)j}$

$K(t)=\frac{|\b\r T'(t)|}{\bar r (t)|} \\\\=\frac{|-\sin t i+\cos t j|}{|7t\cos t +7t \sin t j|}$

Using eq (1) and (2)

$K(t)=\frac{\sqrt{(-\sin t)^2+(\cos t)^2} }{\sqrt{(7t\cos t)^2+(7t\sin t)^2} }\\\\=\frac{\sqrt{\sin^2 t+\cos^2t} }{\sqrt{49t^2(\cos^2 t+\sin^2t)} }\\\\=\frac{\sqrt{1} }{\sqrt{49t^2\times 1} } \\\\ \large \boxed {K(t)=\frac{1}{7t} }$

7 0

3 years ago

Estimate by rounding to the nearest hundred.<br>Show your work.<br>12,846 - 3467

Rufina [12.5K]

Answer:

9,400

Step-by-step explanation:

12,846 - 3,467 = 9,379

The hundreds digit is 3.

So, you look to the left of the digit and if it is 5 for more you add a number to the 3 and make the rest of the digits 0s. But if it below 5, then you leave the 3 alone and make the rest of the digit going to the right 0s.

Then, your answer is (9,400)

Hope this helps ; )

3 0

3 years ago

Use the spinner to identify the probability to the nearest hundredth of the pointer

Blizzard [7]

The answer is 0.60 because the sum of the shaded angles equals 145°, divided by 360° equals 0.60

4 0

3 years ago

In 2007, the first generation of the i-phone sold for $499. The average cost of an i-phone today is $999. At a press conference

Gwar [14]

Answer: the statement made by Tim Cook is TRUE

Step-by-step explanation:

Given that;

in 2007 cost of 1st gen iphone = $499 (base year price)

cost of iphone today = $999 (current year price)

Using the Consumer Price Index

the Consumer Price Index = (cost pf product in current years/cost of product base year) × 100

we substitute

CPI = (999/499) × 100

CPI = 200.2004

so the CPI is 100.2004% higher in the current year than in the base year

Checking the inflation rate

IR = (( CPI this year- CPI last year)/CPI last year) × 100

CPI last year (base year) = 100

CPI current year is = 100.2004

so

IR = (( 100.2004 - 100)/100) × 100

IR = 0.002004 × 100

IR = 0.2004%

THEREFORE the statement made by Tim Cook is TRUE

3 0

3 years ago

What is missing for the following quantity to be true? 3x + 4y + 7a = 4y + 3x + __

Alex

The answer to your question is 7a.

4 0

3 years ago