What is Trig: Definition and 1000 Discussions

The Renewables Infrastructure Group (LSE: TRIG) is a large British investment trust dedicated to investments in assets generating electricity from renewable sources. Established in 2013, the company is a constituent of the FTSE 250 Index. The chairman is Helen Mahy.

View More On Wikipedia.org
  1. karush

    MHB Finding the Value of a Trigonometric Integral with Radical

    Evaluate $$\int_0^{2\pi}\sqrt{\dfrac{1-\cos{x}}{2}}\,dx$$ ok my baby step is $$\int _0^{2\pi }\frac{\sqrt{1-\cos \left(x\right)}}{\sqrt{2}}dx$$ then ? W|A said the answer was 4
  2. karush

    MHB 7.2.1 integrate trig with radical

    Ok I tried to follow an example but kinda got lost in this maybe more steps the answer is from W|A
  3. H

    I Nearly constant 0 result from a trig function

    Interpolating a straight line with a trigonometric function. In Matlab I ended up with this expression. fplot(@(x)(.0000001*cos(x*2*pi)+10), [0 1]) Would anyone like to discuss what this could be used in?
  4. J

    Exploring the Solutions of Trigonometric Equations: 2tanx= 1/2tan2x

    2tanx= 1/2tan2x 4tanx=2tanx / 1 - tan^2x 1- tan^2x = 2tanx / 4tanx tan^2x = 1/2 tanx = √1/2 Textbook answer 0 ; +/- 0.615 rad Not sure where I am going wrong.
  5. Like Tony Stark

    How to get ##\ddot r## when you have ##r##, ##\theta## and right trig

    I have a right triangle: one of the angles is ##60°## (that's ##\theta##), one of the sides is ##40 m## long, and the hypotenuse is equal to the radius. Now I can find an expression for ##r## and that expression is ##r=\frac{height}{sin \theta}##. If I differentiate it, I'll get ##\dot r## and...
  6. S

    MHB Solving trig equation cos(x)=sin(x) + 1/√3

    Hello, I'm trying to solve the following equation : cos(x)=sin(x) + 1/\sqrt{3} in order to find cos(x)3 - sin3(x) = ? i tried to slove for sin(x) using sin2 + cos2 =1 replacing cos(x) by the first equation and i end up with a second degree polynomial using x = sin(x) and there are 2...
  7. Zbaldridge

    Schools College Algebra And Trig at the same time?

    I am currently a community college student majoring in Computer Science, and I was placed into Calculus 1. I had to withdraw from this course for two semesters now. My professor advised me that I have "Algebra Issues". With my weaker foundation of Algebra, I plan to take the College Algebra...
  8. karush

    MHB Prove trig identity (cot x -1)/(cot x +1)=(1-sin 2x)/(cos 2x)

    $\begin{align*} \frac{\cot {x}-1}{\cot{x}+1}&=\frac{1-\sin 2x}{\cos 2x}\\ \frac{\cos {x}-\sin x}{\cos{x}+\sin x} \frac{\cos x-\sin x}{\cos x-\sin x}&= \\ \frac{\cos^2x-2\sin x\cos x+\cos^2 x}{\cos^2 x-\sin^2 x} \end{align*}$ so far..
  9. Zack K

    Using Trig Substitution in Trig Integration

    Homework Statement Integrate: $$\int \frac{dx}{x^2\sqrt{4-x^2}}dx$$ Homework EquationsThe Attempt at a Solution I got to the final solution ##\int \frac{dx}{x^2\sqrt{4-x^2}}dx=-\frac{1}{4}cot(arcsin(\frac{1}{2}x))##. But It's the method where you transform that to the solution...
  10. C

    Trig function equation: d=4(sin5t-4cos6t)

    Homework Statement 1. A weight hangs from a spring. If a force is applied to the weight at t = 0 seconds, it will start moving up and down. The following equation gives the distance d, in centimetres, of the weight from its equilibrium point: d=4(sin5t-4cos6t) At what times during the...
  11. A

    Mastering Trig Identities: Simplifying a Trig Expression

    The other day in a fit of boredom I decided to dust off my old math books (high school and undergrad) and see if I can still crank through the basics. 1. Homework Statement Show the following: $$ \frac { 3 cos^2(x) } { 2 - 2 sin(x) } = \frac { 3 }{ 2 } ( sin(x) + 1 ) $$ Homework Equations $$...
  12. T

    B Trig Problem Altitudes of Parallelogram

    Basically the altitudes of a parallelogram have two lengths, 8 and 10 and they intersect at an angle whose sine is 1/4. I'm attempting to find the area of the parallelogram. I'm having trouble creating a good picture of it. Seeing if I could receive some help, thanks!
  13. Lilian Chan

    What is the net force on the -1nC charge in this Coulomb's Law problem?

    Homework Statement link: https://ibb.co/Xy9s6DR What is the magnitude of this force? Homework Equations Coulomb's Law Trig equations The Attempt at a Solution (.05 m)xcos(60)=0.025m (the distance between the two known charges) F(between the two known...
  14. opus

    B How would I write this trig solution?

    If I want to find the point where the graphs of ##y=cos^2(x)## and ##g=sin^2(x)## intersect, I would set the equations equal to each other and solve for the ##x##. This solution is ##x=sin^{-1}\left(\frac{\sqrt{2}}{2}\right)=\frac{π}{4}+2nπ,\frac{3π}{4}+2nπ##. However these the graphs do...
  15. opus

    Trig Integral Homework: Solving \int_0^{π/8}sin^2(x)cos^2(x)

    Homework Statement ##\int_0^{π/8}sin^2(x)cos^2(x)## Homework EquationsThe Attempt at a Solution Please see my attached work to see the train of thought. I've tried this thing about 100 times and still can't get the correct solution. I don't know if it's in the anti derivative evaluations of...
  16. T

    I Exploring the Connection between Trigonometric and Exponential Functions

    Hi all: I really do not know what to ask here, so please be patient as I get a little too "spiritual" (for want of a better word). (This could be a stupid question...) I get this: eiθ=cosθ+isinθ And it is beautiful. I am struck by the fact that the trig functions manifest harmonic...
  17. Cheesycheese213

    B Applications of Morley's Theorem

    I was planning to do an essay exploring Morley's Trisector Theorem, but I was having trouble finding and real life applications of it? It states that "in any triangle, the three points of intersection of the adjacent angle trisectors form an equilateral triangle". I thought it was pretty...
  18. R

    MHB Trig Functions: When Plugging in x Returns x

    I have the statement \sin[\sin^{-1}(x)] = x \hspace{7pt} if -1 \leq x \leq 1. How can I tell if plugging in x will return x for \cos[\cos^{-1}(x)] and \tan[\tan^{-1}(x)] ? What if the positions of the regular and inverse functions were reversed? For example, \cos^{-1}[\cos(x)]. I am only...
  19. karush

    MHB 7.3.5 Integral with trig substitution

    $\textsf{Evaluate the integral}$ $$I=\displaystyle\int\frac{x^2}{\sqrt{9-x^2}}$$ $\textit{from the common Integrals Table we have}$ $$\displaystyle I=\int\frac{u^2}{\sqrt{u^2-a^2}} \, du =\frac{u}{2}\sqrt{u^2-a^2}+\frac{a^2}{2} \ln\left|u+\sqrt{u^2-a^2}\right|+C$$...
  20. K

    Trig problem involving a triangle's angles and sides

    Homework Statement In the triangle ABC, angle A = 30 deg, angle B = 45 deg and since AC = a. The perpendicular from C on AB cuts AB in E. In this task you should calculate exact values. a) Determine AE, BC and AB expressed by a. b) Perpendicular from B on AC intersects the extension of AC in...
  21. barryj

    How to solve this math problem: Two simultaneous trig equations

    Homework Statement I worked a physics problem and the answer came down to solving these two equations and I am stuck. Homework Equations [/B] 2 equations and two unknowns. sin(x) = (2/3)sin(y) 1 + cos(x) = (2/3) cos(y) The Attempt at a Solution I tried this and it went nowhere.. z...
  22. C

    Solving System of Equations (including Trig)

    Homework Statement This is an example worked out in the textbook Matter and Interactions, 4th Edition (pg. 181). The authors assume that solving for two unknowns is no problem, so they don’t show the steps. I’m trying to work it out and am stuck. I’ve used Alpha to get a step by step solution...
  23. F

    Trouble developing trig expression

    Homework Statement It's not a problem per se, I'm just trying something, so there's no statement. What I'm trying to do it's to prove the forllowing equation but without using the member of the right. (cos(36º) + 1)²/(cos(36º)) = 5cos(36º) There's the trivial answer, using both members, that...
  24. opus

    Constructing accurate diagrams of word problem- Trig

    Homework Statement A canoe is floating down a creek. The canoe is first spotted 80 feet away. 7 minutes later the canoe is 45 feet away, making a 40° angle between the two sightings. How far did the canoe travel? Homework Equations Law of Sines and Law of Cosines The Attempt at a Solution...
  25. C

    MHB Tan (Theta - Pie) Answer Explained

    What does Tan (Theta - Pie) = ? I know Tan (theta + pie) = tan (theta). They say the answer is tan (theta), but I think it's some kind of typo.
  26. C

    MHB Trig Graphing Questions: Given graph find the function

    How do I solve these? https://imgur.com/a/NvzxFcS
  27. karush

    MHB How do you rewrite the given equation as a function of u(x)?

    $$\displaystyle y^\prime +(1/x)y = 3\cos 2x, \quad x>0$$ first how do you get $u(x)$ from this
  28. opus

    Help Simplifying a Trig Expression

    Homework Statement Simplify: $$sin^2\left(x\right)+sin^2\left(x\right)tan^2\left(x\right)$$ Homework Equations All trigonometric identities. The Attempt at a Solution (i) ##sin^2\left(x\right)+sin^2\left(x\right)tan^2\left(x\right)## (ii)...
  29. opus

    Inverse Trig Functions and Reciprocals

    Homework Statement Evaluate and express your answer in radians: $$cot^{-1}\left(1\right)$$ Homework EquationsThe Attempt at a Solution I start by identifying that the domain of Arccotangent is all real numbers. So 1 is in the domain. From here, I looked at the unit circle and saw that...
  30. L

    MHB Why is Angle C Assumed to be Acute and What is the Value of Sin C in ∆ABC?

    Given that √5 tanA=-2 and CosB=8/17 in ∆ABC State why we may assume that angle C is acute and determine the value of Sin CAttempt made: tanA=-2/√5 CosB=8/17 A is obtuse angle of 138° or reflex angle 318.19° B is an acute angle of61.9° or reflex angle298.1 °.Since it is a right...
  31. gibberingmouther

    B Brushing Up Math Knowledge: Basic Trig Questions

    i'm going back to school in September. I'm brushing up on my math knowledge/skills now and thinking of maybe joining a math club when i am back in school. I've often thought if i had an expert to talk to i could learn math a lot quicker than relying on just written instruction ... so maybe i...
  32. adamaero

    Why does the trig expression just disappear?

    Homework Statement Homework Equations 3. Solution Then the equations from part (A) are used--but why does the converted trig (1-cos(etc)) go away? Does this have to do with the mean-squared bit?
  33. opus

    Trig Identities -- example problem confusion

    Homework Statement Back with more trig identities. Verify that the following is an identity ##-tan\frac{a}{2} = cot\left(a\right)-csc\left(a\right)## Homework Equations All pythagorean identities, double angle formulas, half angle formulas The Attempt at a Solution In the picture that I've...
  34. M

    MHB Evaluate Trig Expressions....Part 2

    Evaluate the trig expressions using the method shown in the textbook. Steps A through C show the method given in the textbook. 1. cos 4π/3 A. We are told to graph cos 4π/3. We are in Quadrant 3. B. Find the reference number r. r = 3π/2 - 4π/3 r = π/6 C. Evaluate r. cos π/6 = -sqrt{3}/2...
  35. M

    MHB Evaluate Trig Expressions....Part 1

    Evaluate the trig expressions using the method shown in the textbook. Steps A through C show the method given in the textbook. 1. sin 210° A. We are told to graph sin 210°. We are in Quadrant 3. B. Find the reference angle R. R = 270° - 210° R = 60° C. Evaluate sin R. sin 60° = -sqrt{3}/2...
  36. opus

    Using Power Reducing Formulas to rewrite Trig Expressions

    Homework Statement Use the power reducing formulas to rewrite the expression that does not contain trigonometric functions of power greater than 1. Given expression: ##4sin^2xcos^2x## 2. Homework Equations Relevant Power-Reducing Formulas: ##sin^2x=\frac{1-cos2x}{2}##...
  37. M

    MHB Approximating Trig Values using the Unit Circle

    The following question, in my opinion, is not well-explained in Section 6.2 by David Cohen. I went over the question several times but it is not clear at all. Use the picture to approximate the following trig values to within successive tenths. Then use a calculator to check your answers...
  38. M

    MHB How can I determine the biggest trig value without a calculator?

    How do I determine which trig value is bigger or smaller without using a calculator? Sample: Which is bigger: cos 2 or sin 2?
  39. Saurabh

    Solve Hairy Trig Integral: Find Value of 'c

    <Moderator's note: Moved from a technical forum and thus no template.> where a, b, c, d and n, all are positive integers. Find the value of 'c'. ------------------------------- I don't really have a good approach for this one. I just made a substitution u = sinx + cosx I couldn't clear up...
  40. alijan kk

    Understanding the Derivative of Inverse Trig Functions

    Homework Statement why this formula works ? Homework EquationsThe Attempt at a Solution when i take the derivative of the right side ,,, there is an additional "a" in the numerator in place of 1,, why the derivative of arcsine of (u/a) not exactly same with the expression under the integral sign
  41. C

    Calculus 2 - Trig Integrals Question (Integrating cos^2x)

    1. Here's the problem on trig integrating that I'm struggling with (Calculus 2 btw) 2. Wanted to see if I did everything right so far and what to do after all this. The part where I'm stuck is how to integrate (integral)cos^(2)udu and (integral)cos^(2)usin^(2)udu. I'm sure these are easy...
  42. OldWorldBlues

    B Using trig to find distance?

    Hi there! I haven't yet taken a trigonometry course (I'm in High-school), but I have an amateur interest in surveying. Recently I began thinking about how I could calculate the height of a point relative to me, or the distance of the object from me. Naturally, I immediately thought of the...
  43. sparkie

    Using reference angles to evaluate trig function

    Mod note: Moved from a Homework section, as this is more of a conceptual question than an actual homework problem. I can't really memorize the unit circle, but I do remember my instructor teaching us how to use reference angles to evaluate any trig function without needing the unit circle. I was...
  44. S

    Solving trig equation with TI Ispire CX

    Homework Statement solve xsin(x)-cos(x)=0 on interval (0,4) using the calculator Homework Equations xsin(x)-cos(x)=0 The Attempt at a Solution I have tried working the problem out through first pressing menu- 3 (algebra)- 1 (solve)- inserting the equation- inserting the interval. However...
  45. M

    Proper usage of trig functions in force problems

    Not a particular problem to wonder about but more of a general question, when one has a free body diagram, when is it best to use sine and when is it best to use cosine? I am reviewing some of my tests for a final, and having previously re-read my forces chapter, I thought that angles rising...
  46. T

    Solving for the third one should be straightforward.

    Homework Statement Completely solve this triangle. No calculators please. A=? B=Pi/3 C=? a=(1+sqrt(3)) b=? c=2 Homework Equations Cosine law: b^2=a^2c^2-2ac(cos(B)) Sine law: Sin(A)/a=Sin(B)/b The Attempt at a Solution b^2=-6 You can plug in 1/2 in (cos(B)) right away. Other attemps, don't ask...
  47. F

    I Finding the explicit solution of a trig equation

    Hello, I understand that solving an equation like f(x)=0 means finding those values of x that make the equality true. In the case of some difficult trig equations (like sin(x)+tan(3x+2)+cos^2(x)=5 which I just made it) it may not be possible to find an explicit solution. What does that mean...
  48. karush

    MHB Evaluate Integral $t_{1.11}$: $\cos^3$ to $\cos$

    $\tiny{t1.11}$ $\textsf{Evaluate the Integral}$ \begin{align*}\displaystyle I_{11}&=\int \frac{\sin\sqrt{t}}{\sqrt{t\cos^3\sqrt{t}}}\, dt\\ &=\int\frac{\sin\sqrt{t}}{\sqrt{t}\cos^{3/2}\sqrt{t}}\, dt\\ u&=\cos\sqrt{t}\\...
  49. J

    Geometry: Solve for angles of a triangle w/line intersecting

    My mother's boyfriend's son who is in 6th grade asked me a question about the math they are learning. I thought it wouldn't be too bad but I cannot for the life of me figure it out. A solution would be greatly appreciated. 1. Homework Statement https://postimg.org/image/1tsa4v4t8r/ Homework...
  50. T

    Can Trig Ratios Solve for Theta in a Physics Homework Problem?

    Homework Statement Sino - ucos o =x Homework Equations N.A. The Attempt at a Solution I am asking if it's possible to make theta(o) the subject of formula in relation to some physics homework which I narrowed down to this but I don't know how to solve for theta, x is a known value but it's...
Back
Top