MATH 1201 Unit 7 WA Official Solution PDF

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1 MATH 1201Written Assignment 7 – Official Solution1. Find the length of an arc in a circle of radius 10 centimeters subtended bythe central angle of 50 °.SolutionWe have푙푒푛푔푡ℎ= 50! 360 !× 2 휋푅=50 360 × 2 × 3. 14 × 10 푐푚=5 9 × 3. 14 × 5 푐푚≅ 8. 73 푐푚. 2. Graph f (x) = x sin x on [-4π, 4π] and verbali...

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MATH 1201 Written Assignment 7 – Official Solution 1. Find the length of an arc in a circle of radius 10 centimeters subtended by the central angle of 50°. Solution "

We have 50! 𝑙𝑒𝑛𝑔𝑡ℎ =

360!

×2𝜋𝑅 =

5 50 ×2×3.14×10 𝑐𝑚 = ×3.14×5 𝑐𝑚 ≅ 8.73 𝑐𝑚." 9 360

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2. Graph f (x) = x sin x on [-4π, 4π] and verbalize how the graph varies from the graphs of 𝑓 𝑥 = ±𝑥. !"# !

Graph 𝑓 𝑥 = ! on the window [−5π, 5π] and describe freely what the graph shows. You can use www.desmos.com/calculator to obtain the graphs. Solution

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3. A 23-ft ladder leans against a building so that the angle between the ground and the ladder is 80°. How high does the ladder reach up the side of the building? Show the steps of your reasoning. Solution We have sin 80! =

ℎ𝑒𝑖𝑔ℎ𝑡 𝑜𝑓 𝑏𝑢𝑖𝑙𝑑𝑖𝑛𝑔 23

→ 0.985 =

ℎ𝑒𝑖𝑔ℎ𝑡 𝑜𝑓 𝑏𝑢𝑖𝑙𝑑𝑖𝑛𝑔 → 23

→ 0.985×23 = ℎ𝑒𝑖𝑔ℎ𝑡 𝑜𝑓 𝑏𝑢𝑖𝑙𝑑𝑖𝑛𝑔 → 22.651 ft = ℎ𝑒𝑖𝑔ℎ𝑡 𝑜𝑓 𝑏𝑢𝑖𝑙𝑑𝑖𝑛𝑔. """"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""" " " " "

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