Question

derivative of
d²y/dx²=cos 2x-y​

Answer 1

Answer:

$\green\bigstar$ correct answer

what we have here is a function 2x inside another function cos .

This is known as a function of a function.

If we differentiate cosx we get - sinx

when we differentiate cos2x we get - sin2x but then have to differentiate 2x.

This can be written as y = cos2x

⇒dydx=−sin2x.ddx

2

x

)

=

−

sin

2

x

.

2

⇒

d

y

d

x

=

−

2

sin

2

x