Question

@loser66 If sin y= cos 3y, determine an exact value for angle y.

Answer 1

I think I just got one of many of the solutions for this question by fluke.

Answer 2

Heres how I went about doing it.

\[\sin y= \cos 3y\]
\[\frac{ \sin y }{ \cos 3y }=1\]
\[\tan (\frac{ 1 }{ 3 }y)=1\]
\[\frac{ y }{ 3 }=\frac{ \Pi }{ 4 }\]
\[y=\frac{ 3\Pi }{ 4 }\]

Is my method correct or was it just a fluke?

Answer 3

nope, it is not valid , since \(\dfrac{siny}{cos 3y}\neq tan(y/3)\)

Answer 4

yea I thought so Thanks for confirming

Answer 5

so how would I go about doing this?

Answer 6

I am sorry, I don't have time for now.

Answer 7

@iambatman