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The Math District
United States
เข้าร่วมเมื่อ 26 พ.ย. 2017
Welcome to The Math District!
I teach college math classes in the United States, and I have created this channel to provide easy to follow videos on a large variety of math topics.
I hope you will learn a lot! Thank you for watching.
I teach college math classes in the United States, and I have created this channel to provide easy to follow videos on a large variety of math topics.
I hope you will learn a lot! Thank you for watching.
วีดีโอ
How to Convert Polar Coordinates to Rectangular Coordinates with Example.
มุมมอง 6214 ชั่วโมงที่ผ่านมา
Learn how to deduct the formulas that convert polar coordinates to rectangular coordinates. x = r cos θ y = r sin θ
Find the Radius of a Circle Inscribed in a Right Isosceles Triangle.
มุมมอง 25317 ชั่วโมงที่ผ่านมา
How to find the radius using the Pythagorean theorem and the two tangents theorem.
The Polar Coordinate System: One Point - Multiple Representations
มุมมอง 47วันที่ผ่านมา
In the Polar Coordinate System each point has many infinitely representations. Learn about the formulas you can you to find multiple representations of the same point.
How to Plot Points in the Polar Coordinate System
มุมมอง 9614 วันที่ผ่านมา
Learn about the Polar Coordinate System, how to plot points, and how to use the Polar Coordinate Grid.
Can You Find Side x? Put Your Trig Skills to the Test!
มุมมอง 20521 วันที่ผ่านมา
Use the Law of Sines and the Law of Cosines to solve the problem.
Find Angle θ. Two Methods - Which One You Would Use?
มุมมอง 20221 วันที่ผ่านมา
Use trigonometry to find angle θ.
Shape Up Your Geometry Knowledge! Find the Area of the Triangle AOB.
มุมมอง 12221 วันที่ผ่านมา
Learn about properties of parallelograms and the choice of formulas for the area of a triangle.
How to Use The Law of Cosines to Solve a SSS Triangle with an Example
มุมมอง 11528 วันที่ผ่านมา
Learn about the steps you need to solve a SSS triangle and the alternative options.
How to Use The Law of Cosines to Solve a SAS Triangle. IN-DEPTH EXPLANATION.
มุมมอง 142หลายเดือนก่อน
The video explains how to solve a Side-Angle-Side Triangle and why the following steps work. Use the Law of Cosines to find the side opposite of the given angle. Use the Law of Sines to find the angle opposite the shorter of the two given sides. Find the third angle by subtracting the other two angles from 180°.
The Law of Cosines - How to Deduct the Angle Formulas.
มุมมอง 157หลายเดือนก่อน
Learn how to deduct the angle formulas from the Law of Cosines.
Find the Radius r. Intriguing Geometry Challenge.
มุมมอง 242หลายเดือนก่อน
Learn how to apply multiple geometry principles to find the radius of the circle.
Can You Find Angle α? Geometry Challenge!
มุมมอง 335หลายเดือนก่อน
Inside a right triangle, ∠ADB=45°, ∠CAD=15°, AB=5, BD=5, ED=DC. Learn how to find ∠α.
The Law of Cosines - The Proof Using Trigonometry and the Pythagorean Theorem
มุมมอง 122หลายเดือนก่อน
Learn how to prove the Law of Cosines using Trigonometry and the Pythagorean Theorem.
The Law of Cosines - What if Angle C=90°?
มุมมอง 185หลายเดือนก่อน
Learn about the transformation of the Law of Cosines when angle C is 90 degrees.
The Law of Cosines - The Proof Using the Distance Formula
มุมมอง 1962 หลายเดือนก่อน
The Law of Cosines - The Proof Using the Distance Formula
Find the Perimeter of △ABC if AD = 5.
มุมมอง 3642 หลายเดือนก่อน
Find the Perimeter of △ABC if AD = 5.
Using the Law of Sines to Solve an SSA Triangle(The Ambiguous Case with Two Triangles)
มุมมอง 2452 หลายเดือนก่อน
Using the Law of Sines to Solve an SSA Triangle(The Ambiguous Case with Two Triangles)
How to Find the Area of a Circle Given Two Perpendicular Chords. Geometry Challenge
มุมมอง 4382 หลายเดือนก่อน
How to Find the Area of a Circle Given Two Perpendicular Chords. Geometry Challenge
Use the Law of Sines to Solve an SSA Triangle (The Ambiguous Case with No Solution)
มุมมอง 1723 หลายเดือนก่อน
Use the Law of Sines to Solve an SSA Triangle (The Ambiguous Case with No Solution)
Use the Law of Sines to Solve an SSA Triangle (The Ambiguous Case with 1 Solution)
มุมมอง 1523 หลายเดือนก่อน
Use the Law of Sines to Solve an SSA Triangle (The Ambiguous Case with 1 Solution)
How to Solve an ASA Triangle Using the Law of Sines
มุมมอง 1563 หลายเดือนก่อน
How to Solve an ASA Triangle Using the Law of Sines
How to Solve an SAA Triangle Using the Law of Sines
มุมมอง 1773 หลายเดือนก่อน
How to Solve an SAA Triangle Using the Law of Sines
Solving Triangles Using the Law of Sines - Three Cases: SAA, ASA, and SSA
มุมมอง 943 หลายเดือนก่อน
Solving Triangles Using the Law of Sines - Three Cases: SAA, ASA, and SSA
The Law of Sines - Why It Works? (Two Proofs)
มุมมอง 2903 หลายเดือนก่อน
The Law of Sines - Why It Works? (Two Proofs)
How to Find the Coordinates of the Circumcenter Given the Coordinates of the Vertices of a Triangle
มุมมอง 3464 หลายเดือนก่อน
How to Find the Coordinates of the Circumcenter Given the Coordinates of the Vertices of a Triangle
Find the Radius of the Small Circle - Geometry Challenge
มุมมอง 4814 หลายเดือนก่อน
Find the Radius of the Small Circle - Geometry Challenge
Solve the equation csc2x-2 sin2x=1 and find the values of x on [0,2π).
มุมมอง 1684 หลายเดือนก่อน
Solve the equation csc2x-2 sin2x=1 and find the values of x on [0,2π).
Solve the equation tanθ=cotθ and find the values of θ on [0,2π).
มุมมอง 3155 หลายเดือนก่อน
Solve the equation tanθ=cotθ and find the values of θ on [0,2π).
The sum is 11 and the product is 24, so a equals 3. b equals 8. Therefore, 1/a + 1/b = 1/3 + 1/8 = 11/24 The sum is 11 and the product is 24. Answer 11/24
Funny one (tricky too)!!! We can also move as follows: (a+b)/ab=11/24 Bifurcating these we will get (a/ab)+(b/ab)=11/24 Resulting as(1/b)+(1/a)=11/24 But however thanks to you is minimum appreciation.
2.(10-R) = 10 / cos 45° 20 - 2R = 10√2 R = 10 - 5√2 = 2,929 cm ( Solved √ )
[2.(10-R)]² = 2. 10² 4 . (10²-20R + R²) = 200 R² - 20R + 50 = 0 R = 2,929 cm ( Solved √ )
Thank you for these videos! 🌟
You are so welcome!
this is the best way to solve this problem we should always try to use basic methods which we never forgot in future. Good problem and nice solution.
Thanks a lot.
Área ABC =10*10/2=50 =2*(10-r)r+r²→ 10-5√2 =2,92893... ud. Gracias y un saludo.
The radius is 5[2-sqrt(2)]. I checked that the radius is more than zero. This should indicate that I have done a sanity check!!!
I find it highly counter-intuitive. In the notation first is the radius and then the angle. And drawing the point you always 'draw' a line at the correct angle and THEN measure the 'distance' radius.
Really helpful illustrations, thanks for this video!
You're very welcome!
❤
So good and clear. Thank you a lot for this!
You're very welcome! I'm glad my explanation was helpful and easy to understand.
This is challenge that could be used to fine tune youe ability to practice Law of Cosines and Law of Sines.
You are absolutely right. Thank you!
Wonderfully explained, thank you so much!!
You're very welcome! I am glad you enjoyed it.
Done it on my own by finding third side applying cos rules followed by heron's formula. Honour for you 🙏
That's great! Thank you for taking the time and solving the problem independently using the cosine rule and Heron's formula.
The first method was the fastest!!!
Thank you for sharing.
The answer is 48sin(110°). I am kind if glad that there are ways of calculating the area of certain shapes depending on given information. I am planning on mixing and matching problems of subtract other areas type with this type so that I can shapoe my geometry even further!!!
Great job finding the correct answer! I'm glad you are looking into exploring different approaches to solving geometry problems. Keep up the great work.
@@TheMathDistrict I want to be an expert mathematician on par with Srinivasa Ramamujan. Or die trying. And I will do that by mixing and matching problems from a diverse amount of TH-cam math channels!!!
1st: if you calculate all angles with the Law of Cosines you can check the result because all the angles should add up to 180 2nd: you can simplefy the Law of Sines step by calculating the 'triangle factor' (distance over sin(angle)) of the known angle, and calculate the other angles with that number
Good lesson mam. Thanks a lot
It's my pleasure.
You are best teacher I've ever known! Thank you!
Thank you, I really appreciate it.
the circle is called the incircle and the radius, inradius
I solved this by inspection and conjecture. 27 = 9 x 3. Assume, therefore, the long side is 9 sqrt(2). 15 = 3 x 5. Assume, therefore, the short side is 5 sqrt (2). Area of the rectangle is thus 9 x 5 x sqrt(2) x sqrt(2) = 90. Area of blue = 90 - 27 -15 - 12 = 36.
Thank you, I appreciate your content.
You're welcome! I'm glad you find it helpful.
Your explanation was so systematic, clear and easy to understand. Thanks!
You're very welcome! I'm glad my explanation was helpful and easy to follow.
OE^2+EC^2-2*OE*EC*cos(135°)=OC^2=R^2, (COS THEOREM), OE=EF/√2
Love It! Thank you for helping me solve my homework! Life just became much simpler!
Thank you, I'm happy to hear that!
Nicely done.
Thank you, really appreciate it.
It is so useful! Thank you!
Thank you! I appreciate your feedback.
Beautiful question! 👍
Thank you! Cheers!
In competitive exams we have to make use of formulae, we dont have much time.
We have a formula to find out x Product of sides/sum of sides 24x16/(24+16)=48/5
Is 250 is closer to 200 or 300???
Great question! 250 is exactly halfway between 200 and 300. However, if we round it to the nearest hundred, we will round it up to 300. Thank you for watching the video.
24(2π/3-√3/2)-72(π/3-√3/2)=-8π+24 √3
S=9*231^0.5/4 r=231^0.5/6
(a+3)^2+a^2=45 2a^2+6a-36=0 a=(-6+-18)/4=3;-6 a=3 S=9
❤
Love this!
Thank you!
thank you for your explanation♥♥♥♥
Always welcome
a=10, b=9
ar. of inscribed square92.16 sq unit.ans
The way the task was posed must always apply to variable radii of the circle. The radius could therefore be zero, the triangle collapses, the line BC also becomes zero and the former triangle only consists of two lines that are parallel to each other and both have a length of 5. The circumference is therefore 2 * 5 = 10. This solution approach of mine is based solely on the assumption that the task could only be posed in this way if this solution approach works, without discussing the geometric basis for why the task could be posed in this way. The solution in the video is similar to mine, but it contains the complete explanation of why the perimeter must always be 10, and thus also explains why this problem could be posed in exactly this way.
As always, great explanation.
Can also be solved using 'Special Case' argument. Point F can be anywhere in the circle between points D and E. Suppose point B is very very close to point D. In this case line BC is almost the same length as AD. Which gives the clue as perimeter of triangle is 2x5 = 10.
Thank you, liked your explanation.
BD=BF; CE=CF ---> ABF+ACF=AD+AE=5+5=10=AB+BC+CA
Third method is very insightful. Thank you for making this video, I appreciate that you approached it from different strategies.
You're very welcome, and I am glad it was useful!
Excellent explanation
Very helpful!
Glad it was helpful!