Which of the following are equivalent to the function y=3cosx+2? Check all that apply. A. y=3sin(x-π/2)+2

By=-3cosx-2

C.y=3sin(x+π/2)+2

D.y=3cos(-x)+2

Verified Answer :

A.y=3cos(-x)+2 is correct.
D.y=3sin(x+pi/2)+2 is correct.
On apex.

Answer:

Option C and D are the following equivalent to the function y = 3 cos x+ 2

Step-by-step explanation:

Given the function: y = 3 cos x+ 2

Using trigonometry identities:

For odd/ even identities:

  • sin(-x) =-sin x
  • cos(-x)= cos x

Complementary Angle identities:

  • \(\sin x = \cos(\frac{\pi}{2}-x)\)
  • \(\cos x = \sin(\frac{\pi}{2}-x)\)

Option A:

\(y =3\sin(x-\frac{\pi}{2})+2\)

using trigonometry identity:

\(y =3\sin(-(\frac{\pi}{2}-x))+2= -3\sin(\frac{\pi}{2}-x)+2=-3\cos x+2\)

Option B

\(y =-3\cos x -2\)

Option C

\(y =3\sin(x+\frac{\pi}{2})+2\)         [sin(90 +x) = cos x ]

using trigonometry identity, [sin(90 +x) = cos x ];

\(y =3\cos x+2\)

Option D :

\(y =3\cos(-x)+2\)        

using trigonometry identity:

\(y =3\cos x+2\)

Therefore, the following option which is equivalent to y = 3 cos x+ 2 is C and D