Questions on Algebra: Trigonometry answered by real tutors!

Tutors Answer Your Questions about Trigonometry-basics (FREE)

Question 24014: What is the exact value of the trigonometric function:
Sin 240 degrees?
Click here to see answer by rapaljer(4667)

Question 24445: what is the equation of a circle tangent to the y-axis with center (-7,8) in standard form?
Click here to see answer by venugopalramana(3286)

Question 24453: Of the following numbers, which is largest?
(a) cos (0)
(b) cos (Π /6)
(c) cos (Π /4)
(d) cos (Π/3)
(e) cos (Π)
Click here to see answer by josmiceli(9697)

Question 24810: The length of a rectangular is 10 feet more than twice its width. the perimeter of the rectangule is 170feet. find the dimension of the rectangle
please reply me the answer in detail steps. thanks!
Click here to see answer by Paul(988)

Question 24976: i have a question that appears on your site, however as i progressed with my answer i have come to a difficult point and am stuck. this is what i have got so far;
E=Fs
=7sin(t-60)*4sin(t+30) which can use the idenitity-
2sinAsinB=cos(A+B)-cos(A+B)
=0.5(cos((t-60)-(t+30))-cos((t-60)+(t+30)))
=0.5(cos(t-60-t-30)-cos(t-60+t+30))
=0.5(cos(-90)-cos(2t-30))
=0.5*0-cos(2t-30)
And thats where i got up to, i know the answer should some how get to;
-14cos(2t-30)
But i just cannot get there, can you tell me where i am going wrong and point me there please.
this is the question; the displacement of a body is given by s=4sin(t+30), and a force acting upon the body is given by F=7sin(t-60). If the energy of the motion, E, at time t is the product Fs, show that E=-14cos(2t-30)
Click here to see answer by stanbon(57387)

Question 24448: For all real numbers x, cos^2(x) - sin^2 (x)=?
Thanks
Click here to see answer by venugopalramana(3286)

Question 24779: In triangle ABC, b=11, c=18, and angle B=40 degrees. solve the triangle.
Click here to see answer by venugopalramana(3286)

Question 24778: In triangle ABC, AC=7, BC=12, and angle B=35 degrees. solve the triangle.
Click here to see answer by venugopalramana(3286)

Question 24940: What are the definitons of recursive sequence and explicit sequence?
Click here to see answer by venugopalramana(3286)

Question 25683: Hi, i have this question and i dont know how to start it or what i have to actually find. this is the question;
Two vibration, x1=3sin(10t+π/6) and x2=2cos(10t- π/6) where t is in seconds, are superimposed. Determine the time at which the amplitude of the resultant vibration, x1+x2 first reaches a value of 2.
thanks
Click here to see answer by stanbon(57387)

Question 24238: simultaneous equation a. x + 3y = 5 B. 3x + 4y = 54
Click here to see answer by elephantsize(7)

Question 26339: i need help in my algebra 1 in chapter 8-1 exponents
Click here to see answer by longjonsilver(2297)

Question 27039: Hi
Please can you help me find the general solution in radians of the equation

Thank you very much
Click here to see answer by kev82(148)

Question 27110: Please can you solve the following equation for

?
Thank you
Click here to see answer by venugopalramana(3286)

Question 27169: Please can you help me to find the general solution in radians of the following equation
I think I need to use a trig identity but I'm not sure which one or how?
Thank you
Click here to see answer by venugopalramana(3286)

Question 27372: Given cos theta = 24/25 and (0 < x < pi/2)
Evalutate: (a) sin theta (b) sec theta
Click here to see answer by venugopalramana(3286)

Question 27369: Use a calculator to evalutate
(a) sec(-2.8)

and Graph, showing two complete periods
y=-sinx

Thank you.

Click here to see answer by prabhjyot(164)

Question 28402: Please help me solve this equation=>
-780 (degrees) in six triginometric ratio
sin, cos tan, cot, sec, csc
I put it on a graph and i know it goes counterclock wise since it is a (-) after this i landed in the 4th quadrant then i -360+ -360+ -60=-780(degrees)
but i don't know where to go from there or if all this work i have done is right at all. If someone could please try and help me out or guide me in the right direction I would much be appreciative
Click here to see answer by sdmmadam@yahoo.com(530)

Question 28414: Please can someone help me solve this problem
cot A=(3/4) and its in the 3rd quad. find the remaining ratios sin,cos,tan,csc,sec
Click here to see answer by sdmmadam@yahoo.com(530)

Question 28415: find the trig. ratio of the following
cot 180(degrees)
csc -270(degrees)
sec 720(degrees)
Click here to see answer by venugopalramana(3286)

Question 28417: find the angle requested for the following
sin A= .2356(nearest degree) tan A= -2.4567 (nearest sec)
for the sin A i really have no idea what to do but for tan A= -2.4567 do i basically type it into the calc. like this tan (-2.4567)/3600
ok thats probably not right.
thank you very much for helping me out :) you don't understand how much this stuff just goes right over my head because the teacher likes to rush to get all the material covered. Thank you again
Click here to see answer by longjonsilver(2297)

Question 28811: A plane is observed approaching your home and you assume that its speed is 550 miles per hour. The angle of elevation of the plane is 16 degrees at one time and 57 degrees one minute later. Approximate the altitude of the plane. Round to the nearest 2 decimal places.
Click here to see answer by venugopalramana(3286)

Question 28886: How do you simplify this?
(cos2x) / (cosx - sinx)
Click here to see answer by stanbon(57387)

Question 29614: I am trying to integrate the following:
dx/(sin(x)+tan(x))
using u substitution.
I know you can replace dx with 2du/1+u^2 and sin(x) can be replaced by 2u/1+u^2. If possible, please give every detail- I do not understand it and have been trying to do it for a while now! Thanks for your time!
Click here to see answer by shafkat_alam(3)

Question 29677: What is the angle of elevation of the sun when a 35-ft mast casts a 20-ft shadow
Click here to see answer by favegirl13(22)

Question 29702: simplify (1+i)to the 2nd power
Click here to see answer by sdmmadam@yahoo.com(530)

Question 29701: the minimum and maximum of 2x(2x)+1=y-3x
and y=-x(-x)+2x-4
4x^2+3x+1=y
so,y'=8x+3=0[for max]
whence x=-8/3 and y[max]=4*64/3-8/3+1=251/3
similarly for nextone y=-3
Click here to see answer by angshu0070(1)

Question 29703: simplify +-(-2+4i)

Click here to see answer by longjonsilver(2297)

Question 29857: another form of cos(30 degrees-A)+sin(60degrees+A)=
I got sqrt of 3 divided by 2 sin A + cos A
Click here to see answer by venugopalramana(3286)

Question 29858: What is the exact value of sin square pi/ 6 - 2sin pi/ 6 cos pi/ 6 =cos square (-pi/6)?
I got 2-Sqrt3/2
Click here to see answer by venugopalramana(3286)

Question 29856: if 9cos square A+ 3 cos A = 0where 90degrees<0<180degrees what is the value of A to the nearest 10th.
Click here to see answer by venugopalramana(3286)

Question 29855: prove each of the following identities algebraically a. cosA+cosA tan squareA=secA
b.cosA(secA-cscA)=1-cotA
c.Prove the identity sin squareA divided 1-cosA=secA+1 divided by secA
d.Verify sin square x+cos square x=1 for x=5pi divided by 3.Graph y=sin square
x+cos square x and describe the result.Also explain the result.
Thank you so much . This is my first attempt at pure math so i am very bad at it.
Click here to see answer by venugopalramana(3286)

Question 24239: Big final at work, Can't seem to get this one. Simultaneous equation. A. x + 3y= 5 B. 3x + 4y =54 ? HELP!
Click here to see answer by Nate(3500)

Question 30138: for sinA +cosAcotA=cscA
a.Show that the equation is true whenA=30 degrees. use exact values
b.prove the equation algebraically
c.state any restrictions to the equation
Click here to see answer by Paul(988)

Question 30135: Solve sin 2y = cos 4 y for y, where 0 degree <_y<360 degrees
Click here to see answer by sdmmadam@yahoo.com(530)

Question 30136: find the exact values of cos8 degrees cos 38 degrees +sin 8 degrees + sin 38 degrees
Click here to see answer by sdmmadam@yahoo.com(530)

Question 30631: What is the integral of a trigonometric function squared? for example,. sin(squared) of 3x.
Click here to see answer by venugopalramana(3286)

Question 30793: I am trying to solve for t:

I have no idea where to start. Thank you for you help.

Click here to see answer by Fermat(127)

Question 30953: I need help i don't now how to work out this problem.....
Click here to see answer by acerX(62)

Question 30955: solve triangle ABC using the diagram and the given measurements....
B=41 degrees, a=6.8
..A
..|..\
.b|...\ c
..|.....\
..|____\
..C a B
Click here to see answer by ichudov(499)

Question 30955: solve triangle ABC using the diagram and the given measurements....
B=41 degrees, a=6.8
..A
..|..\
.b|...\ c
..|.....\
..|____\
..C a B
Click here to see answer by acerX(62)

Question 30959: solve triangle ABC using the diagram and the given measurements....
A=70 degrees, c=30
A
|\
b| \ c
|_ \
|_|___\
C a B
Click here to see answer by acerX(62)

Question 31257: tan theta + cot theta = 1 over the sin theta times cos theta
It asks me to:
"Verify the Identity. Justify each step."
Click here to see answer by longjonsilver(2297)

Question 31280: The distance between (-1,3) to (5,2).
Click here to see answer by Earlsdon(6287)

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