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MyLab and Mastering Take a Test - Michael Mi xTrig_Cheat_Sheet.doc Mathway Math

ID: 3194672 • Letter: M

Question

MyLab and Mastering Take a Test - Michael Mi xTrig_Cheat_Sheet.doc Mathway Math Problen x C C Secure l https://www.maths.com/Student/PlayerTest.aspx?testld-174340042 Chegg Study Guided Sc x Imported From IE punkin school folder home Renji Michaelsfast food Trigonometry Calcula Sy Trigonometry Cheats G triangle calc: find A Other bookmarks MATH 112 Plane Trigonometry Fall 2017 Intersession Michael Mitchell 1 1/3/18 10:30 AM Quiz: Final Exam Review Submit Quiz This Question: 1 pt 5 of 80 (4 complete) This Quiz: 80 pts possible erify the identity cott- sin 2t-cott cos 2t iate double-angle formula and rewrite the right side of the identity cot t Distribute the cott and rewrite the right side of the equation. The expression from the previous step then simplifies to cott- sin 2t using what? OA. Reciprocal Identity OB. Quotient Identity O C. Pythagorean Identity O D. Even-Odd Identity Click to select your answer(s). l10:30 AM 1/3/2018

Explanation / Answer

Given :

cot t - sin 2t = cot t cos 2t

Solution :

By the double angle identities , we have

Cos 2t = cos2t - sin2t = 1-2sin2t = 2cos2t-1

Substituting value of cos 2t in the given identity , we have

cot t - sin 2t = cot t ( cos2t - sin2t )

Right side of equation : cot t ( cos2t - sin2t )   [ It is first answer after applying double angle formula]

cot t - sin 2t = cot t cos2t - cot t sin2t

cot t - sin 2t = (1/ tan t) cos2 t - cot t sin2t

Cot t - sin 2t = (cos t/ sin t)cos2t - (cos t/sin t)sin2t

cot t - sin 2t = cos3t/sin t - cos t sint

cot t = cos3t/sin t - cost sint + sin 2t

[ sin 2t = 2sin t cos t]

cot t = cos3t/ sin t + sint cos t   [ it is the second answer after distributing the cot t ]

right side of equation: cos3t/sin t + sin t cos t

Correct option : A ( reciprocal identity)    [ last answer]

We have use cot t = 1/ tan t