SOLUTION: How to solve this problem and the steps w/five key points? y = Sin 4x? I'm a beginner can u help?

You can put this solution on YOUR website!
This you really can't solve. You can simplify or graph.
(i)
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Now 4x = 2x + 2x, so we get
(ii)
we have an identity:
sin(A+B) = sinA cosB + sinB cosA
or in our case
(iii)
But these are the same, so we can write
(Iv)
--
Now 2x = x + x, so we get
(v)
we have an identity:
sin(A+B) = sinA cosB + sinB cosA
or in our case
(vi)
But these are the same, so we can write
(vii)
From (iv) and (vii), we get