Trig work problem... (am I correct?)
Homework Statement
If we call the height @ which the supports cross ,x, express this height as an equation in terms of H1 and H2 Only... Use similar triangle...
Are my proportion correct?
x/H1 = (L1-L)/L1
x/H2 = (L)/L1 = (L1-L)/L1
Because Where...
Homework Statement
\int\frac{\sqrt{x^2 + 36}}{4x^2}}dx
Homework Equations
sqrt(a^2 + x^2) substitution for x = a tan theta
The Attempt at a Solution
I set
x = 6 tan theta
x^2 = 36 tan^2 theta
dx = 6 sec^2 x
\int\frac{\sqrt{36 + 36 tan \theta}}{144 tan \theta}dx
\int\frac{\sqrt{36(tan...
Homework Statement
Six Identical pipes, each with radius of 1 foot are ties tightly together with a metal band... Find the length of the metal band...
I posted a picture...
My strategy is dividing the figure in half
Then finding the measure of the two arcs in red ( which should be...
Homework Statement
y = 1/x - sin(x)
What is the best strategy to graph this? I am having a difficult time drawing accurate graphs of these types of functions...
Ok...
(2, -3)
R = (Sqrt x^2 + y^2)
R = (sqrt (2)^2 + (-3)^2)
R= (sqrt 13)^2
R=13
Sin = y/r
Sin -3 / 13 ?
Cosin 2 / 13 ?
But then.. how come the answer gives me sin -3 (sqrt13) / 13 and for cosin 2(sqrt13) / 13
My question is how come there's a (sqrt13) included for the...
Ok- I am teaching trigonometry to low level students right now and I am trying to figure out why they need to know the unit circle. Are there some interesting things they can learn about by using a unit circle?
So far, we pretended it was a magic-barbie-sized-half-underground-ferris-wheel...
Homework Statement
my professor tell me that when looking at the case ∫ √ (a^2 - x^2) , the trig substitution of course is asinϑ where -pi/2 ≤ ϑ ≤ pi/2. What I don't understand is why my professor tells me that when this term, √ (a^2 - x^2), is in the denomenator of the integrand that we must...
This is part of the derivation in EM theory. I try to simplify and be very specific. I don't agree with the book but this book usually is accurate:
I need to find:
cos (\frac {n\pi}{2} + \frac {n\pi x}{2}) \;\hbox { where }\; n= 1,3,5...
The usual way to solve this is:
cos (A+B) =...
I found one of the answers to the problem, and I took a peak, but couldn't find out how the book got the second answer.
Problem-
A batted baseball leaves the bat at an angle of θ with the horizontal and an initial velocity of v0=100 feet per second. The ball is caught by an outfielder 300...
I just want to know, what tan-1x means to you guys? does it mean arctan or cot?
What about tan-2x? Isn't that cot2x? Shouldn't the notation tan-2x be banned to avoid misinterpreting it as an inverse trig function?
Homework Statement
Problem 6. If you know that tan(theta) = -4/5 and sin(theta) > 0, find:
(a) sin(theta)
(b) cos(theta)
(c) tan(theta + pi)Homework Equations
cos^2(t)+sin^2(t)=1
tan(t)=sin(t)/cos(t)
The Attempt at a Solution
My teacher went over this today, but likes to skip over steps that I...
Homework Statement
3(sin(x)^4+cos(x)^4)-2(sin(x)^6+cos(x)^6)=1
(these are sinx raised to the 4 and 6 powers, not x^4or6)
Homework Equations
Pythagorean Identities
The Attempt at a Solution
I've tried using pythagorean identities to change everything to terms of sine or...
Homework Statement
I was reading on the Weierstrass substitution, and I came across the following trigonometric identity:
tan^{-1}(\alpha) - tan^{-1}(\beta) = tan^{-1}\left(\frac{\alpha-\beta}{1+\alpha \beta}\right)Homework Equations
I'm not really sure which equations are applicable here...
Homework Statement
integral of x^2/sqrt(9-25x^2)
Homework Equations
The Attempt at a Solution
dont know how to type theta so I am using @
so i made x=3sin@
dx=3cos@d@...
Homework Statement
Integral of 1/(2+sin(x)) dx
Homework Equations
The Attempt at a Solution
I've been told that you can use trig subs, but I never had to learn that in high school and it hasn't appeared in any of my calculus coursework.
As a side note. I've been wondering if it...
Homework Statement
It's been a couple of years since I've done real math, so I'm kinda stuck on this one. This is actually part of a physics problem, not a math problem - but I'm stuck on the calculus part. I'm trying to solve this guy:
\int \limits_{-\infty}^{\infty}...
Homework Statement
find the volume of a sphere of radius R by integrating over the primary volume elements in cartesian coordinates. Hint: use a trig substitution for your integral over dy
Homework Equations
The Attempt at a Solution
I don't understand what the problem wants me...
When formally proving trig identities using algebra are you allowed to divide? Ordinarily I wouldn't think twice about this. Sure, the trig function by which you are dividing might take on 0, but not for all angles. We divide by potential zeros all the time.
My advisor was being very coy...
Homework Statement
∫ x/(x^2 + x+ 1)dx
Homework Equations
The Attempt at a Solution
∫ x/(x^2 + x+ 1)dx
not really sure where to start on this one, i feel like i should factor the denominator in such a way that i have an expression whose derivative is some constant times x. help please
Homework Statement
This is only a step in a bigger example problem on trig substitution
2/3 *x2 = sin2\theta
\sqrt{}2/3 * x =sin\theta
\theta = arcsin(\sqrt{}2/3 * x)
and
x = \sqrt{}3/2 * sin\theta
This makes sense
Then I saw
dx / d\theta = \sqrt{}3/2 * cos\theta
Uh... why...
Homework Statement
sorry wait a few moments for the details, i hit post on accident prematurely
∫ √(1 + x^2)/x dx
The Attempt at a Solution
∫ √(1 + x^2)/x dx
x = tanϑ , dx sec^2ϑ dϑ -π/2 < ϑ < π/2
√(1 + x^2) = secϑ
∫ (secϑ * sec^2ϑ dϑ )/ tanϑ dϑ
after using trig identities...
Homework Statement
∫ x^2√(a^2 - x^2) dx evaluate integral from 0 to a
Homework Equations
The Attempt at a Solution
so i know the format of this problem requires the substitution of asinϑ -π/2 ≤ ϑ ≤ π/2 , but i don't know how to change the bounds of the integral...
Homework Statement
rock rises straight upward frim the valley floor. From one point the angle of elevation of the top of the rock is 16.7 deg. From a point 168 m closer to the rock the angle of elevation of the top of the rock is 24.1 deg. How high is the rock...
I added an attachment...
Homework Statement
this is the first problem like this I've ever tried so take it easy!:redface:
evaluate the integral
I = ∫ x^3/√(16-x^2) dx from 0 to 2√3
The Attempt at a Solution
- π/2 < ϑ < π/2
x = 4sinϑ , dx = 4cosϑdϑ
*x = 2√3, x/4 = sinϑ , sinϑ = √3/2 , ϑ = π/3
x = 0 sinϑ = 0...
Homework Statement
Find the partial derivative with respect to x of sin(xyz - 1)
Homework Equations
None needed.
The Attempt at a Solution
I took the answer to be yz*cos(xyz - 1), but wolfram alpha is giving me yz*cos(1 - xyz). Anyone know what's going on here? Thanks!
Homework Statement
Find the exact value of each expression:
a) sec-1(\sqrt{}2)
b) sin-1(1)
Homework Equations
sec\theta=\stackrel{}{}1/cos\theta
The Attempt at a Solution
I've never learned this, but I am really curious in how it is solved.
Is there a formula for this? Thanks!
Homework Statement
I am having trouble row reducing...
5cos(t) 5sin(t) | -cos(t)
2cos(t)+sin(t) 2sin(t)-cos(t) | sin(t)
Homework Equations
The Attempt at a Solution
I know I am allowed to multiply a row by a constant but I...
Hello!
I'm having some trouble with finding the fundamental period of the slightly more complex trig functions. I think it's pretty simple stuff but I can't seem to crack it and I really need to get this bit sorted before I can move on with Fourier Expansions.
I can do the more simple...
Homework Statement
Solve for n:
2n.Cos^2(n)=1000
The Attempt at a Solution
So, I think there's a substitution involved here. I tried to rearrange cosine in terms of sine to make it into a quadratic but that didn't work. I've gone through all the table trig identities. I've had other...
In the attached picture there is a right triangle (the right angle is on the right bottom corner). The angle, theta, is on the left-most side. From what i remember, sin (theta) is equal to opposite/hypotenuse. If you can see in the picture, it has written: delta x = h/sin(theta)
so...
Homework Statement
Integral of dx/[(x2 - 2x + 2)2]Homework Equations
Trig substitution rules:
for expression sqrt(a2 - x2)
make x = asin(t) with -(pi/2) < t < (pi/2)
for sqrt(x2 - a2)
make x = asec(t) with 0< t < (pi/2)
and
for sqrt(a2 + x2)
make x = atan(t) with -(pi/2) < t < (pi/2)The...
Homework Statement
What is the importance of knowing how to express trig ratios in terms of sine, cosine, tan, cosec, sec, or cot?
Homework Equations
The Attempt at a Solution
Homework Statement
I have been practicing proving trig. ident. for the past couple of days... although I am getting better... I wanted to ask are there any strategies that I should be aware of to make the process easier ?
Homework Equations
The Attempt at a Solution
\int x^{2} \sqrt{4+x^{2}} dx
I've already subbed in:
x = 2tan\theta
dx = 2sec^{2}\theta d\theta
and I've gotten down to:
16 \int tan^{3}\theta sec^{3}\theta d\theta
But now I have noo idea what to do! Can someone give me a hint?
Homework Statement
Determine the average rate of change of the function y = 2cos (x - pi/3) + 1 for the following internal:
pi/2 < x < 5pi/4
Homework Equations
AROC = [ f(x2) - f(x1) ] / x2) - x1
The Attempt at a Solution
For an approx. value, I would set the calculator in...
Homework Statement
Find number of deg. subtendedat the center of a circle by an arc whose length is 357 times the radius,taking pi = 3.1416...
The Attempt at a Solution
The arc length is... 357(r)
The radius length is r
One revolution = 2r(pi) = arc lenght.
Now I will solve...
Homework Statement
The book states a proof... which says that the ratio of
circumference/Diameter which this ratio is equal to pi which is the same for all circles...
Ok that obviously make sense noting that circumference = Diameter(pi) which equals circumference/Diameter = pi
My...
Homework Statement
\int \frac{cos x}{sin^2(x) - sin(x)-6}2. The attempt at a solution
I first tried factoring the denominator.
\int \frac{cos x}{(sin(x) -3)(sin(x)+2)}
The first thing that came to my mind was Partial Factoring but I don't think it would work in this case.Thanks in advance!
Problem
Distance:
From city A to city B, a plane flies 650 miles at a bearing of N 48° E. From city B to city C, the plane flies 810 miles at a bearing of S 65° E. Find the distance from A to C and the bearing from A to C.
Work so far
So far I've gotten the distance from A to C already...
Homework Statement
Hey, I've been working through a book and one problem just gets me that I know should be a piece of cake. I don't know if I'm just being an idiot or not seeing something but the problem is to take int e^(ax)cos(bx)dx and int e^(ax)sin(bx)dx simultaneously by multiplying the...
Homework Statement
I came across this interesting Trig problem that involves an angle θ formed by two rays OB and OA. there are two circles, one with radius a and one with radius b, on on the ray OA that are both tangent to one another. The ray OB is tangent to both of the circles.
Show...
Homework Statement
Evaluate the trigonometric expression (several examples). Hint: In each case, sketch a right triangle. For example, in the first case, sketch a right triangle with a hypotenuse of length 5 and one leg of length 3. Let A be the angle opposite the side of length 3. Solve...
Homework Statement
Hello.
I came across a question that required me to solve for invariant points between a base trig function and the function after horizontal stretch. I can't remember the exact question right now, but I'm just wondering how I would go about solving it if I didn't know...
Hi all. I have to solve this simultaneous trig equation and I am stumped. Can anybody give me a worked solution please?
b*cos 30 = 1375*cos theta (i)
b*sin 30 + 1375 sin theta = 1500 (ii)
I end up with:
b= 1375cos theta / cos 30
substituting into (ii)
1375 cos...
Homework Statement
This is taken from a much larger problem, but I only need the answer to one particular question. Please help me understand why the height that a pendulum swings is r(1-cos\theta) where r is the length of the string and theta is the angle it swings through.Homework Equations...
Homework Statement
Indefinite Integral
(x^3)sqrt((x^2)+4)dx
Homework Equations
With an x= 2tan@
and dx= 2 (sec^2)@ d@
The Attempt at a Solution
I get to
8(tan^3)@(sqrt((4tan^2)@+(8sec^2)@d@
Simplified down to
8(tan^3)@(sqrt((12tan^2)@+8d@
After that I'm stuck
The...
Homework Statement
tan 2x = 8cos^2 x - cot x. Solve where x 0 ≤ x ≤ pi/2
Homework Equations
The basic trig identities
The Attempt at a Solution
I tried many different things which all eventually led to no solution. Firstly I tried solving the problem as I would a rational...
Homework Statement
the problem is:
tan(theta) = cos(theta)
find theta: -pi < theta < pi
Homework Equations
tan(theta)=sin(theta)/cos(theta)
sin^2(theta)+cos^2(theta)=1
The Attempt at a Solution