L
=
∫
t
f
t
i
√
(
d
x
d
t
)
2
+
(
d
y
d
t
)
2
d
t
. Since
x
and
y
are perpendicular, it's not difficult to see why this computes the arclength.
It isn't very different from the arclength of a regular function:
L
=
∫
b
a
√
1
+
(
d
y
d
x
)
2
d
x
. If you need the derivation of the parametric formula, please ask it as a separate question.
We find the 2 derivatives:
d
x
d
t
=
3
−
3
t
2
d
y
d
t
=
6
t
And we substitute these into the integral:
L
=
∫
√
3
0
√
(
3
−
3
t
2
)
2
+
(
6
t
)
2
d
t
And solve:
=
∫
√
3
0
√
9
−
18
t
2
+
9
t
4
+
36
t
2
d
t
=
∫
√
3
0
√
9
+
18
t
2
+
9
t
4
d
t
=
∫
√
3
0
√
(
3
+
3
t
2
)
2
d
t
=
∫
√
3
0
(
3
+
3
t
2
)
d
t
=
3
t
+
t
3
∣
∣
√
3
0
=
3
√
3
+
3
√
3
=6The arclength of a parametric curve can be found using the formula:
L
=
∫
t
f
t
i
√
(
d
x
d
t
)
2
+
(
d
y
d
t
)
2
d
t
. Since
x
and
y
are perpendicular, it's not difficult to see why this computes the arclength.
It isn't very different from the arclength of a regular function:
L
=
∫
b
a
√
1
+
(
d
y
d
x
)
2
d
x
. If you need the derivation of the parametric formula, please ask it as a separate question.
We find the 2 derivatives:
d
x
d
t
=
3
−
3
t
2
d
y
d
t
=
6
t
And we substitute these into the integral:
L
=
∫
√
3
0
√
(
3
−
3
t
2
)
2
+
(
6
t
)
2
d
t
And solve:
=
∫
√
3
0
√
9
−
18
t
2
+
9
t
4
+
36
t
2
d
t
=
∫
√
3
0
√
9
+
18
t
2
+
9
t
4
d
t
=
∫
√
3
0
√
(
3
+
3
t
2
)
2
d
t
=
∫
√
3
0
(
3
+
3
t
2
)
d
t
=
3
t
+
t
3
∣
∣
√
3
0
=
3
√
3
+
3
√
3
=
6
√
3
Be aware that arclength usually has a difficult function to integrate. Most integrable functions look like the above where a binomial is squared and adding the two terms will flip the sign of the binomial.
Be aware that arclength usually has a difficult function to integrate. Most integrable functions look like the above where a binomial is squared and adding the two terms will flip the sign of the binomial.
Angles TRS and VRW are vertical angles, so we can set them equal to each other to get x:
x+40=3x
40=2x
20=x
So the value of x is 20
Hey there!
Okay let's get cracking :D
The equation is.... (2x/3) - 6 = 9
2x/3 = 15
2x = 45
<u>x = 22.5</u><u /> <----- And that is your answer!
I hope it helped!
<u>Please vote for me as Brainliest if there is a second answer!</u>
1.)
Old Number:35
New Number:45
Now, subract the new number(45) from the old number. (35)
45-35 is 10. Now divide the old number (35) by 10.
You'll get 3.5. 3.5%, increase is the answer for #1.
2.) Old: s (students)
New: 36,750
Do 100+5 (Addition because we do not know what the old number is.) 100+5 is 105. Move decimal over twice and you get 1.05. Multiply 36,750 by 1.05.
There were 38,587.5 kids last year.
3.)Since the discount is 15% off, do 100-15=85. Now, move the decimal over from the percent, and that makes that .85. Now multiply 50x.85. You get 42.5, or $42.50. Now the coupon is 10%, So subtract 100-10, giving you 90. Now move the decimal over. .90. Multiply 42.5 (or 42.50) by .90. You get 38.25. You do have enough money.
4.) Subtract 100-15, giving you 85. Move decimal over from percent. .85.
Now you would multiply .85 times k. B should be the answer.
There is no solution is the answer. I had this in one of my math tests so I'm positive it's correct :D
