Circle Area

 

source: @Math26039335 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Answer: 2/3

 

Square area

 

Source: @SWCHS_Maths

 

 

 

 

 

Goat Inside a Square Barn

Source and answer: Quanta 

 

Sine, Cosine and Area of Triangle Tasks

 

Modeling the Motion on Cosmo Clock 21

 

This is Cosmo Clock 21, the giant Ferris wheel located in Minato Mirai. Its height from the

ground is 112.5 meters and it has a rotating diameter of 100 meters. It finishes one rotation

in about 15 minutes.(Source)

-------

A student rides on Cosmo Clock 21 for two rounds. 

1.Graph this two round-ride modeling the relationship between the student’s height from

the ground with respect to time. 

2. Find a cosine function that is modeling your graph in the form of y=acos(b(x-c))+d.

Show every step explaining how you find a, b, c and d. Explain each variable, including

y and x, how you find them and their meaning in the context of this problem. 

3. At what times will the student be at 100 meter altitude from the ground? Explain.

4.Write a short reflection explaining the degree of your accuracy.

Justify the possible elements or factors making your model and your answer to question

3 inaccurate.

Full solution steps

Some student answers:

y = 50cos((2π / 15) (t - 15/2 )) + 62.5 {0 <= t <= 30 }

y=-50cos(2pi/15)t+62.5 {0<=t<=30}

 Or y=50cos(2pi/15)(t-7.5)+62.5 {0<=t<=30}

Two Trigonometric Functions

 

Many Angles Same Result

 

Sine Wave From A Cylinder

a slice through a cylinder creates an ellipse. when unrolled, it creates a sine wave pic.twitter.com/Mrl5Gcd3A4

— Matt Henderson (@matthen2) June 25, 2020

 

Problem 147: Sine and Cosine Rules Practice

resource: Don Steward

Problem 129: Congruent rectangles

Three Congruent Triangles. What is the angle?

source: Catriona Shearer

Problem 105: Orienteers

Two orienteers start running from the same point with bearings of 050 and 210 degrees respectively.

After 23 minutes they covered the same distances. The distance between them at this time is 9 km. What is their average speed?

Problem 103: Tangent x

Resource and solutions: MathCeyhun

Problem 102: Trigonometry Length and Angle Calculations

Problem 100: Cosine Rule Exercise

Problem 64: Rolling Rectangle

This question is moderated from Brilliant.org's Weekly quiz for this week. The original question can be reached from this link.

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