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Trigonometry
Trigonometry is a field of mathematics. It is the study of triangles. Trigonometry includes planar trigonometry, spherical trigonometry, finding unknown values in triangles, trigonometric functions, and trigonometric function graphs.
3,810 Questions
How do you solve sin 2 theta if sin theta equals 3 over 5 and theta is in the second quadrant?
""Inasmuch as many have taken in hand to set in order a narrative of those things which have been fulfilled among us, just as those who from the beginning were eyewitnesses and ministers of the word delivered them to us, it seemed good to me also, having had perfect understanding of all things from the very first, to write to you an orderly account, most excellent Theophilus, that you may know the certainty of those things in which you were instructed.""
How trigonometry used in geography?
Principally in surveying by triangulation: you divide the countryside into imaginary adjacent triangles, each lying on a plane in three-dimensions (E-W, N-S and altitude) between defined points on the ground, so a lot of advanced trigonometry is necessary to calculate the co-ordinates of the triangles' apices. Nowadays large-areas maps are generated from satellite images but triangulation is still necessary for small-scale work such as in building and civil-engineering detail mapping and setting-out.
The ratio of the spacing of the fingers and the distance from your eye will be the same as the ratio of the height of the object to its distance from you, so Hf/Df = Ho/Do and Do = HoDf/Hf
Where does the word restroom come from?
- == People used to rest and read the newspaper in a room. they did not want to get up and use the bathroom while they were resting so they added it to the restroom! ==
It actually comes from the Days before labor laws . people would work 18 hr days with no breaks . going to the bathroom was there only form of rest .
How do you solve trigonometry problems?
Check out these articles for a simple free tool and tutorial that will make trig simple enough for ANYBODY to understand!
http://www.ehow.com/how_5520340_memorize-trig-functions-losing-mind.html
http://www.ehow.com/how_5227490_pass-mind-part-unknown-sides.html
http://www.ehow.com/how_5428511_pass-part-ii-unknown-angles.html
How do you find tan 20 without using calculator?
There is no simple way. You could use published tables but I don't suppose that is what you meant.
What is the strategy for finding the cube root of complex numbers?
Here's how you can find any power (fractions would be a root of a number) of any number (complex or real). A real number is a subset of the complex number set, with the imaginary part = 0. I'll refer you to a related link on Euler's formula for information about how this is derived. A complex number can be graphed on the Real-Imaginary plane, with reals on the horizontal axis, and imaginary on the vertical. Convert the complex number from x-y style coordinates in this plane to polar coordinates.
For a complex number a + bi, here's how you do that. We will end up with a magnitude and an angle. The magnitude is sqrt(a² + b²). The angle is found by tan-1(b/a). Now to find a power, apply the power to the magnitude (for cube root this is exponent of 1/3). Then multiply the angle by the power (in this case you divide by 3). Really for a cube root there will be 3 distinct roots. Since a the angle of a circle is 360° or 2pi radians, you can add 2pi radians to the angle of the original complex number, then divide by 3 to determine the second root. Add 4pi radians to the original angle and then divide by 3 to determine the 3rd root. Then convert back to x-y coordinates if you want to:
Magnitude*(cos(angle) + i*sin(angle)), for each of the 3 angles that you determined.
See the question: 'Strategy for finding the cube root of complex numbers'
What is the Formula for a acute triangle?
For acute triangle None of the angle of triangle should be more than 90 degrees. See the weblink below for formulas.
Using Pythagoras' theorem the height of the house is 5 times the square root of 7 or about 13.229 feet rounded to three decimal place
How do you solve trignometric identities?
tan(x) = sin(x)/cos(x)
Therefore, all trigonometric ratios can be expressed in terms of sin and cos. So the identity can be rewritten in terms of sin and cos.
Then there are only two "tools":
sin^2(x) + cos^2(x) = 1
and sin(x) = cos(pi/2 - x)
Suitable use of these will enable you to prove the identity.
How do you find the hypotenuse with a cosine and or sine?
For a right angle triangle:-
hypotenuse = adjacent/cosine or hypotenuse = opposite/sine
What is the Formula for calculating chord length?
Assume you mean the chord of a circle? If the angle between the two radii from the ends of the chord is A, and the radius of the circle is R, the chord length L will be
L = 2RsinA/2. You can prove this easily by joining the point bisecting the chord to the centre, you then have two rightangled triangles, with an included angle of A/2, and an opposite side of L/2. So sinA/2 = L/2R.
All pyramids have an odd number of edges?
False. In fact, the opposite is true: all pyramids have an even number of edges.
Square root of 3 sinx plus cosx equals 0?
sqrt(3sin(x)=cos(x)=0 // Square both sides
3sin(x) + cos(x) = 0 // subtract cos(x) from both sides
3sin(x) = -cos(x) // rearrange
sin(x)/cos(x) = -1/3 //sin(x)/cos(x) = tan(x)
tan(x) = -1/3
x = tan^-1(-1/3) == -18,43484882 // tan^-1(inverse tan)
How do you solve the trigonomic equation sin2x equals negative cosx?
Sin(2x) = -cos(x)
But sin(2x) = 2 sin(x) cos(x)
Substitute it:
2 sin(x) cos(x) = -cos(x)
Divide each side by cos(x):
2 sin(x) = -1
sin(x) = -1/2
x = 210°
x = 330°
When is the angle are said to be in standard position?
When the beginning ray of the angle is on the x-axis.
What does a marine biologist use?
They examine animals and sea creatures and do research on their life cycle and their numbers to make sure they are not in danger of becoming extinct
What are the two types of trigonometry?
Trigonometry based on a unit circle and radians and trigonometry based on a right triangle.
Find the area of a sector. Do not round?
Because you will be using the number pi to find the area of the circle, some rounding will be required.
What are the plationic solids?
Platonic solids are convex regular (equiangular) polyhedra. There are five Platonic solids: the tetrahedron, or pyramid (four equilateral triangles for faces; traditionally associated with the element Fire), the octahedron (eight equilateral triangles; traditionally associated with Air), the icosahedron (twenty equilateral triangles; traditionally associated with Water), the cube (six squares for faces; traditionally associated with Earth), and the dodecahedron (which has twelve regular pentagons for faces and is associated with the legendary Luminiferous Aether that had often been considered an element). These are the only existing regular polyhedra that exhibit convexity; other, non-convex regular polyhedra (meaning that there are angles between some of their faces that are less than 180 degrees as measured from the outside surface) exist and are known as star polyhedra.
