Find the differential of :
I'm not sure what the 'differential' means, or how to find dy.
A differential is defined as
In essence, you find , and then multiply both sides by to get the equation I defined above.
Can you try to do the problem now?
Yes, I get dy = x(3xcos(3x) + 2sin(3x)) dx
But how do I find dx? In other words, I need dy without dx anywhere in the equation. Is it possible to substitute something in for dx?