Which trigonometric expressions equal ? Check all that apply.




Multiplying both sides of the above equations by r, we get that x = r cos(θ) and y = r sin(θ).
definition of cosine✔ definition of sinePythagorean theorem
definition of cosinedefinition of sine✔ Pythagorean theorem
multiplicationsimplification✔ substitution
associative propertydistributive property✔ laws of exponents
Which trigonometric values equal 0? Check all that apply.sin(3π)cos(–360°)tan(900°)cot(0°)

Given and , use trigonometric identities to find the the value of cot(30°).





Given , what is cos(t)?





A bicycle wheel with diameter 16 inches rides over a screw in the street. The screw is on level ground before it punctures the bike’s tire. After the bike has moved forward another 56π inches, how high above the ground is the screw? Round to the nearest tenth of an inch.
A regular hexagon inscribed in a circle creates 6 equiangular triangles. If the radius of the circle is 10 inches, how far are points at A and B from the y-axis?




By , cos(θ) = , and by , sin(θ) = . Multiplying both sides of the above equations by r, we get that x = r cos(θ) and y = r sin(θ). The states that x2 + y2 = r2. By , we have[r cos(θ)]2 + [r sin(θ)]2 = r2. Applying the , the equation can be written as r2 cos2(θ) + r2 sin2(θ) = r2. Dividing both sides of the equation by r2 results in cos2(θ) + sin2(θ) = 1.
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