HW009 Problem 6 Previous Problem List Next 1 point Fillin th

HW009: Problem 6 Previous Problem List Next (1 point) Fillin the blanks below appropriately to obtain a proof for the expression tan(A) . (2083(A)-cos(A)) = sin(A)-2 sin\"(A) Proot: tan(A) (2 cos (A) - cos(A) (2 cos (A)-cos(A) = sin(A)-( =sin(A) , (2-2. = sin(A)-(1- = sin(A)-2sin\"(A) Your goal is to There may be other ways to prove the original ldenty but this problem requires the correct ogie using this approuch in the blanks with appropriate formulas to make adjacent expressors equal Note: You can earn partial creait on this problem Preview My Answers Submit Answens You have attempted this problem 0 times You have unlimted attempts remaining

Solution

tanA ( 2cos^3A - cosA)

= sinA/cosA( 2cos^3A - cosA)

= sinA*2cos^2A - sinA

= sinA( 2cos^2A -1)

=sinA( 2(1- sin^2A ) -1 )

= sinA ( 2- 2sin^2A -1)

= sinA( 1-2sin^2A)

= sinA -2sin^3A