Homework Statement
Evaluate integral sqrt(x^2-9)/x dx
Homework Equations
The Attempt at a Solution
I get this for my answer sqrt(x^2-9)+3sin^(-1)(3/x)+c which is apparently wrong because when I take the derivative of it I don't get the integrand
my work is a attachment in this post
wolfram...
Homework Statement
Evaluate
integral dx/sqrt(1-2x^2)
Homework Equations
The Attempt at a Solution
My Answer: -cos^(-1)(sqrt(2)x)/sqrt(2) + c
See my work in attachment
Wolfram Alpha Answer: (sin^(-1)(sqrt(2) x))/sqrt(2)+constant...
Homework Statement
Evaluate
integral dx/sqrt(x^2-49)
Homework Equations
The Attempt at a Solution
SEE POST #4 BELOW WITH ATTACHMENT TO VIEW MY SOLUTION EASIER TO READ
i was trying to use a csc(theta) substitution and I don't see how my logic and math below is flawed but apparently I'm...
Evaluate
integral sqrt(9-x^2)/x dx
I get to here
-3 ln|csc(sin^-1(x/2)+cot(sin^-1(x/3))|+3cos(sin^-1(x/3)+c
I plugged in for theta because originally I had this
-3 ln|csc(theta)+cot(theta)|+3cos(theta)+c
and I set x equal to a expression
x=3sin(theta)
Hence i had to...
Homework Statement
Evaluate
integral csc(x)^4/cot(x)^2 dx
Homework Equations
The Attempt at a Solution
Apparently I'm doing something wrong, what I'm not sure, thanks for any help
My Answer: 2*tan(x) - (sec(x)^2*tan(x))/3 + c
integral csc(x)^4/cot(x)^2 dx
used fact that...
Homework Statement
Evaluate integral( sin^3(x) cos^5(x) ) dxHomework Equations
sin^2(x) + cos^2(x) = 1
integral x^n dx = x^(n+1)/(n+1) + c
d/dx cos(x) = -sin(x)
a^n*a^m=a^(n+m)
The Attempt at a Solution
I got -cos^6(x)/6+cos^8(x)/8+c
Apparently I did something wrong
SEE ATTACHMENT
Thank...
Homework Statement
Apparently I'm doing something wrong. I'm kind of lost as to what because I looked over my work several times.
Homework Equations
sin^2 x = ( 1 - cos 2x )/2
cos^2 x = ( 1 - sin 2x )/2
integral sin(x) dx = -cos(x)
integral cos(x) dx = sin(x)
The Attempt at a...
Homework Statement
This is a question from my test paper.
If sec \theta=\frac{4xy}{(x+y)^2}, where x,y \in R, then
(a)x,y \in R+
(b)x,y \in R-
(c)x=y\neq0
(d)x\inR+, y\inR-
Homework Equations
The Attempt at a Solution
I don't understand what i have to do and where should...
Homework Statement
integrate xarctanx/(x^2 + 1)^2
Homework Equations
Integration by parts possibly? I was attempting to do it without integration by parts because we went over this in tutorial and my TA couldn't solve it properly, hence why I'm here.
The Attempt at a Solution
I...
Homework Statement
I understand that y = sin -1 x. However, why is it that when one writes x = sin y, one leaves out the -1
Homework Equations
The Attempt at a Solution
I know that when you invert a trig function, the dependent variable essentially switches from y to x and the...
Homework Statement
Use 2 or more substitutions to find the following integrals
hint : begin with u=cosx
Homework Equations
Integral 0--->pi/2 (cosxsinx)/swrt(cos2x+49 dx
The Attempt at a Solution
I'm still a little fuzzy on using multiple substitutions. From what I've read on...
I'm trying to figure out the steps required to do the following simplification:
This equation:
b/(a^2+ ω^2 )*(-a*sin(ω*t)+ω*cos(ω*t))
can be simplified to the following:
(b/√(a^2+ ω^2 ))*sin(ω*t+ θ)
θ= tan^(-1) (- ω/a)
I can numerically verify that this is true but I am having...
Homework Statement
Find the Derivative of:
(ln(cos4x)) / 12x^2
Homework Equations
y' ln(x) = 1/x
The Attempt at a Solution
I have determined the correct answer, but I am still confused as to how I came to the solution. Starting with the numerator, the derivative of cos...
Having Trouble: Solving a Trigonometric Equation using Identities ?
Homework Statement
I am having problems with these. Need some help please!
Here is a sample question I am having troubles with:
3 cos θ + 3 = 2 sin^2 θ, 0 <= θ < 2pi
I am really struggling with these. Any help...
Homework Statement
\int(cosx)^5sin(x)dx, the question asks me to simply find the integral.
Homework Equations
cos^2(x) + sin^2(x) = 1
The Attempt at a Solution
I have an odd power of cosine so I should split that up into [cos^2(x)]^2(sin(x)cos(x)), then I change cos^2(x) to...
I want a timeline for trigonometric function and how it was developed. Just like who created it and stuff like that. Did the greeks know about trigonometric functions? Is a tangent in calculus the same as a tangent in trigonometry and the function os a trigonometry? How do trigonometric...
Homework Statement
A boat leaves the harbor going 60 degrees north-east with the speed 20km/h. 3 hours later, another boat leaves a harbor 160km to the east with a speed of 70km/h. What course should the second boat have to meet the first?
Homework Equations
Not 100% sure what equations would...
e.g. I want to find y when x is at pi/2 for the graph y=cos pi x. Why does pi/2 have to be expressed as a 'normal' (for want of better word) number (3.14/2) and not as 90 degrees (180/2) like you would for a graph without a pi in it
e.g. cos x
For cos x, if x is at pi/2, then I just put in...
Hi,
I was asked to solve for this:
sin (2x) = sin (0.5x)
For 0 to 270 degrees
I know how to solve it by plotting the two graphs, is there any other way of doing it, like, for example, algebraically?
Thanks,
Peter G.
1. Hi, I have a pre-calculus final tomorrow, and there are a few questions I don't understand.
I'd truly appreciate it if you could help :)
1. If sin(theta)=1/4, theta in quadrant II, find the exact value of cos(theta+pi/6)
2. sin(sin^-1(2/3) + cos^-1(1/3)) -- simplify
3...
Hi,
3sin(2x) = sin (x)
I managed to find two answers: 80.4 Degrees and 279.6 degrees but I don't know hot to get 0, 180 and 360 as answers, can anyone help me?
This is how I found the two other angles:
6 sin (x) * cos (x) = sin (x)
cos (x) = sin (x) / 6 sin (x)
cos (x) = 1/6
Thanks in...
Hi :smile:
So, this is what I have to solve: 2sin2x - sin x = 0
I got two possibilities:
sin x = 0.5
sin x = 0
From the second equation:
I got 0 and 180, or, in other words, 0 and 3.14. The book has these two answers but the only other answer it has is 6.28 (and by the way, my domain is 0...
Hi :smile:
A weight hangs on the end of an elastic string. The weight is pulled down and released from rest at time t = 0. The length x centimeters of the string at time t seconds is given by the formula: x = 7 - 2sin(πt)
a) Sketch the graph of x against t for 0 <= x <=4
b) Find the two...
Homework Statement
t = tetha
FInd sin 2t when cos t = 4/5
Homework Equations
no idea
The Attempt at a Solution
no. . . . btw what should I do 1st? I don't understand this question
So, in integrals that lead to inverse hyperbolics and can be solved with trigonometric substitution i just get lost. I know how to use both of them but i don't know which to use.
For the sake of simplicity i'll just go with this one
∫ dx/sqrt(4+x^2)
We know this equals arcsinh(x/2)...
Dear all,
Homework Statement
Draw behavior around (0,0) of solutions to the following nonlinear system
\left(
\begin{array}{c}
x'(t) \\
y'(t)
\end{array}\right) =\left(
\begin{array}{cc}
cos {x(t)} + sin {x(t)} + {x(t)}^2 + {x(t)}^2{y(t)}^3 \\
-x(t) + {y(t)}^2 + y(t) + sin {y(t)}...
Homework Statement
For the angle shown a point is given on its terminal arm. Calculate the values of the three reciprocal trigonometric ratios, accurate to 4 decimal places if necessary.
below is the link of the picture referring to the question
https://www.virtualhigh...
Homework Statement
I took a test in my Precalculus class about 3 weeks ago, and the tests were handed back this week. I saw that I didn't do so well because I was stumped on this equation:
3sinx + 4cosx = 1
Homework Equations
We were to use the following formulas to solve this equation...
i have solved some questions but my answers don't match with the solution list i have in my book... please if you help me check my answers, i'll be very grateful..
√3 tan x - sec x - 1 = 0 ... i get three solutions to this question but my book's got two... it doesn't mention 5pi/3 + 2n*pi...
solve the trigonometric equations
tan 2(theta) + cot(theta) = 0
When i solved this question, i got pi/2 + 2n*pi and 3*pi/2 + 2n*pi ... but my book says the answer should be pi/6 + n*pi and 5pi/6 + n*pi
Is my answer wrong?? if so, then what's your solution.?
Homework Statement
Find x
base of triangle: 2 pieces, 8+12
opposite end: x
angle: \Theta ; angle formed by triangle of 8 units and x : 2\Theta
Homework Equations
tan\Theta = opp/adj
tan 2\Theta = 2tan/1-tan2
The Attempt at a Solution
tan\Theta= x/20
tan 2\Theta = x/8...
Homework Statement
Solve the contour integral
\int_{\gamma}\frac{2+z}{1-cos\left(z\right)}dz
along a counter-clockwise circle of radius 1 centered at z=6
Homework Equations
Cauchy's integral formula
f\left(z\right)=\frac{1}{i*2\pi}\int_{\gamma}\frac{f\left(w\right)}{w-z}dw
The...
Homework Statement
Find all solutions to the following equation:
sin((5*x/2)+15)=0.433
where 0 < x < 360
Homework Equations
The Attempt at a Solution
i can find the first value of x that satisfies this equation.
(5*x/2)+15=sin^-1(0.433)
5*x/2=10.6581
5*x=21.2162
x=4.2632...
\intop_{-\pi/2}^{+\pi/2}\sqrt{(-6sin2t)^2+\sqrt{6}(cost)^2}dt
how to solve it?
i tried
by parts and it looks very bad and complicated
edit
sorry i copied the wrond integral
now it fine
Homework Statement
TanΘ = 4/3
pi < Θ < 3pi/2
Find...
a.) Sin(2Θ)
b.) cos(2Θ)
c.) Sin Θ/2
d.) Cos Θ/s
The Attempt at a Solution
So...
The line will be in quadrant III.
Would sin = 4 and cos = 3?
What I used for a.) is ...
a.) Sin(2Θ) = 2sinΘcosΘ
=...
I'm on mobile so I can't use latex..
sin^2 theta - cos^2 theta is not the same thing as one?
If I had a problem say... 1 + cos^2 theta would that equal to sin^2 theta? Or -sin^2 theta? Thanks
Homework Statement
2.) Solve
x7=1
I am to solve for all the solutions to this polynomial, including the complex solutions using trigonometry. I'm supposed to plot my solutions on the unit circle, with the x-axis being the real axis, and the y-axis being the imaginary (or complex) axis...
Homework Statement
Tan \Theta = 12 / 5, sin\Theta<0Homework Equations
Sin ^{2} \Theta+ Cos ^{2}\Theta = 1
The Attempt at a Solution
Sin is less than 0 so... it should be somwhere in the II or III quadrant?
What identities should I use to solve?
Homework Statement
This problem came up while solving a physics problem in waves.
We have the equation cos(96πt)cos(4πt)=0
How many times does the L.H.S. become 0 during the time t=0 to t=1s ?
The Attempt at a Solution
Nothing.
This is more of a trig question but its coming out of an integration problem I am dealing with...
the initial problem is...
\int\frac{\sqrt(1+x^2)}{x}dx
I've worked through the problem with the book and down the line I have to integrate csc(theta) without using a handy-dandy table...
Homework Statement
sec 3\Theta = 2
Find all solutions within 0 < \Theta < 2\Pi
Homework Equations
none
The Attempt at a Solution
I am having trouble "knowing" what angles satisfy sec = 2 within the interval.
I can find one... ArcCos 1/2 = 1.047... which I can guess is...
a*sin(x)=b*sin(th)+c*sin(y)
d+a*cos(x)=b*cos(th)+c*cos(y)
Find x and y if all others are constants. I don't get how to solve this system of trigonometric equations in matlab. Please help me out friends.
Thanks in advance.
Homework Statement
Prove:
lim (n→0) {(sin n cos n) / (ⁿ√(1 - tan² 2n + tan⁴ 2n - tan⁶ 2n + ...))} = 1Homework Equations
The Attempt at a Solution
The denominator is an infinite geometric series, using the sum formula of an infinite geometric series, I simplify the limit:
lim (n→0) {(sin n cos...
Homework Statement
Find the limit as x approaches 0 of xsin(1/(x^2))
Homework Equations
The Attempt at a Solution
I think this goes to 0, because the sine component just oscillates between 1 and -1, and gets multiplied by 0, for all x. I don't know how to show this using limit...
Homework Statement
Prove
http://img847.imageshack.us/img847/9428/trig.png
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Homework Equations
I am not quite sure how to prove this,
I can see it involves using a double angle formula (see http://mathworld.wolfram.com/Double-AngleFormulas.html)...
I am not quite sure how to prove this,
I can see it involves using a double angle formula (see http://mathworld.wolfram.com/Double-AngleFormulas.html).
I have tried working backwards but to no avail.
Any ideas?
http://img847.imageshack.us/img847/9428/trig.png
Uploaded with...