408,832 views
7 votes
7 votes
Hi this is part of my homework I'm struggling with so, if possible, please show me how to Use the power-reducing formulas to rewrite the expression as an equivalent expression that does not contain powers of trigonometric functions greater than one.6 sin⁴ x

User Rick Glimmer
by
2.4k points

1 Answer

21 votes
21 votes

Answer:


(3[3-4\cos(2x)+\cos(4x)])/(4)

Explanation:

Given the trigonometric expression:


6\sin ^4x

By the power-reducing formula for the fourth power:


\sin ^4x=(3-4\cos(2x)+\cos(4x))/(8)

Therefore:


\begin{gathered} 6\sin ^4x=6\mleft[(3-4\cos(2x)+\cos(4x))/(8)\mright] \\ =(3)/(4)\mleft[3-4\cos (2x)+\cos (4x)\mright] \\ \implies6\sin ^4x=(3\lbrack3-4\cos (2x)+\cos (4x)\rbrack)/(4) \end{gathered}

An equivalent expression is:


(3[3-4\cos(2x)+\cos(4x)])/(4)

User UncleDave
by
2.8k points