Question

If Y=1+cos2x so d^2 y/(dx)^2+ 4y=??

Answer 1

Step-by-step explanation:

y = 1+cos2x

d^2 y/dx^2 +4y =????????

d(dy/dx) / dx + 4y

d{d(1+cos2x)/dx} /dx + 4(1+cos2x)

d(-2sin2x) /dx + 4 + 4cos2x

= (-2) d(sin2x) /dx + 4 + 4cos2x

= (-2) × 2cos2x + 4 + 4cos2x

= -4cos2x + 4cos2x + 4

=4