The Law of Sines
All of these trig functions come in real handy for finding the sides and angles of right triangles, but what about oblique triangles? If a triangle doesn't have a right angle, SOHCAHTOA doesn't apply. What do we do?! Don't worry, there are other ways to use these trig functions with oblique triangles, and one of them is called the law of sines. This relates the sides and angles of oblique triangles, so let's make sure that we know how to use it.
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Thank you this really helped me while trying to learn in this pandemic
If anyone is interested, there is an extended law of sines saying that a/sin(A)=b/sin(B))c/sin(c)=2R, where R is the circumradius. Proof: Consider a triangle ABC an its circumcircle: Consider the antipode D of A. We then have 2R/(sin(90°))=2R=sinAB/sin(
would you also make some videos on spherical triangles. you are excellent. please do it if possible. thanks for your efforts.
Great intro!
U r really gud at explaining
Thanku sir .You know lot about maths also.
How To Add, Sub, Divide And Multiple Degrees WithOut Calculator
In 2:52 sir what mode did you use to solve the problem
@elgatogaming4198
19 күн бұрын
The triangle is invalid, thats why in the end he yaps about the formula thats gonna be used (but he didn't showed us how :(
can do a video on laplace transform or shift property????? Dave that is my request
Confused because I can’t do the equation on calculator and I keep getting it wrong.
These videos are gonna save me.
Like law of cosine does law of sins also work on right angle triangle?
if i go to church i am going to pray for your health
@Sh4dowbanned
8 ай бұрын
Damn I should learn saying that BS as a trick
@peterokon7666
5 ай бұрын
@@Sh4dowbannedllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllmplllllllllllllllllllllllllllllllllllllllllllllllllllplllllllllplllllllllllll
@sejirbenothmen7652
3 ай бұрын
@@Sh4dowbanned going to church is now a BS ?
do a fourier series video or conditional probability
Great explanation. Thanks a lot 😊
Sir. Is it a problem if I used a calculator to solve these?
@requity224
2 жыл бұрын
No
do we use radical or degree in the calculator
@carultch
3 жыл бұрын
You mean radian or degree mode. It depends on what angle units you are given / you are expecting, for the problem in question. In a class that focuses on geometry, you'll probably be using degrees. In a class that focuses on calculus, you'll probably be using radians. If you haven't learned what a radian is yet, you most likely would be using degrees for these functions, since this is the angle unit we are taught to use first.
This example is in my book thanks.
Thanks!
I am uni student from California hello hope I get to see you
Sir what is value of cos(-225 degree)
@fmsrfleetmanager6838
4 жыл бұрын
And cot(-300 degree) tan(-150 degree)
@ProfessorDaveExplains
4 жыл бұрын
Start from the beginning of my trigonometry playlist and I promise you will answer those yourself withe ease!
@fmsrfleetmanager6838
4 жыл бұрын
Thanks
@fmsrfleetmanager6838
4 жыл бұрын
Well this are answer's of all three Questions after watching all trigo series. Cos(-225 degree) = +1/root2 cot(-300 degree) = - 1/ root3 tan(-150 degree) = -1/root3
@fmsrfleetmanager6838
4 жыл бұрын
I think so they are all correct
Sir can we find the velus of trigonometric functions without calculator ,,,if yes then tell me how???
@carultch
3 жыл бұрын
There are a select-few special angles where you are expected to memorize the expression for the exact value of these functions (or know how to derive it). Such as sin(30 degrees) = 1/2, and cos(30 degrees) = sqrt(3)/2. These are based on special angles of 30, 45, and 60 and equivalent angles in other quadrants. You should also be able to evaluate integer multiples of 90 degrees without a calculator, by keeping track of the general pattern of these functions. For other angles: You could draw a unit circle to scale and measure the x and y coordinates at a given angle to get the sine and cosine. You could look it up in a trigonometry table the way we had to do before calculators. You could use a slide rule to evaluate these functions. You could evaluate the Taylor polynominal to enough terms for the precision you desire.
@junaidsabri9367
3 жыл бұрын
@@carultch brilliant explanation 👌👌 wish you best of luck
@junaidsabri9367
3 жыл бұрын
@@carultch sir one more question please......if we have perp=4 and base= 4 and hyp=5 the angle between adjacent sides is *x* then sinx= 0.6 ,,and cosx= 0.8 ,my question is that what does is means of0.6 and 0.8🤔
@carultch
3 жыл бұрын
@@junaidsabri9367 That example is not possible as a right triangle, because it doesn't meet a^2+b^2=c^2. You are probably thinking of the 3-4-5 special case of a right triangle that meets the Pythagorean theorem with three integers. Given a base of 4 cm and a height of 3 cm, you'll get a hypotenuse of 5 cm. The sine of the angle with the base will be 3cm/5cm which equals 0.6. The cosine of the angle with the base will be 4cm/5cm which equals 0.8. It is the ratios of the height and base to the hypotenuse. Does this answer your question?
@junaidsabri9367
3 жыл бұрын
@@carultch its ok it is ratio of height and base with hypotenuse .....but what does it means physically ? It's a real problem for me😡🤔 sir I want touse it physically ..and I hope I will do it under your superb guidance🙏🙏
Done.
3:17 Ah, yes. In jr high, this problem with the SSA triangles was creatively expressed with the following quip: showing your ASS (triangle) in class is no good.
Don't call us Shirley
Ah yes, my favorite teacher turned political commentator
@ProfessorDaveExplains
Жыл бұрын
This is a math tutorial, sweetie.
@03e-210a
Жыл бұрын
@@ProfessorDaveExplains It's great stuff man. Thank you
@BlackPill-pu4vi
Жыл бұрын
@@ProfessorDaveExplains Just discovered your channel. I got a zinger for ya to add if you decide to do this lesson over again. Get an old slide rule and show how much easier it is to find the answers. All I need is ONE ratio and everything else is there on the sin / D scales (or sin / A scales if its calibrated that way). So glad I kept mine (shows how old I am)
whats up dude i have a b omb
Ha first like and comment
@SerperiorChaos
3 жыл бұрын
ha not really