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Trigonometric and Polar Functions

Fifteen topics on periodic change. The unit circle as the engine behind sine, cosine, and tangent, sinusoidal functions with amplitude, midline, period, and phase, transformations and context modeling, the tangent and reciprocal functions, inverse trig with its restricted ranges, equation solving that keeps every solution, and polar coordinates with the curves they draw.

Topics
Key forms For every problem in this unit
General sinusoid
f(x) = a·sin(b(x − h)) + k
Amplitude
|a| (distance midline to peak, never negative)
Period
2π/|b| for sin and cos; π/|b| for tan
Midline
y = k
Phase shift
h, read only AFTER factoring b out of the argument
Pythagorean identity
sin²θ + cos²θ = 1
Tangent
tan θ = sin θ / cos θ (undefined where cos θ = 0)
Polar to rectangular
x = r·cos θ,  y = r·sin θ
Rectangular to polar
r² = x² + y²,  tan θ = y/x (quadrant-checked)
Inverse trig ranges
arcsin: [−π/2, π/2] · arccos: [0, π] · arctan: (−π/2, π/2)
Unit 3 tools
Challenge bank
1 / 60

60 open-ended problems.

Read the question, work it out, then flip the card to compare your reasoning to the worked solution. Mark each card so you can return to the ones that still bite.

0 mastered · 0 to revisit · 60 total
Question
Tap card to reveal explanation
Worked solution
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Cumulative assessment

Test the unit.

Twenty mixed items drawn from across all 15 topics, with guaranteed misconception-code coverage. Identifies which misconceptions still bite when you cannot see which topic the question came from.

20questions
15topics
15codes covered
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Course so far

Check what stuck.

Units 1 through 3, drawn evenly so earlier units get the same share as this one. Twenty questions or a full 40-question section, your choice. Even coverage means this is a retention check rather than a score estimate.

20 or 40questions
44topics
43codes covered
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