Which of the following is a sinusoid

Question

Which of the following is a sinusoid?

 

A). x^2+y^2=1

B)x^2/3 + y^2/6=1

C). cuberoot(x) 

D) y=cos(x)-2

 

I am thinking it's D....is that correct?

Could someone explain what a sinusoid is?  At school they didn't explain it very well to me.

Answer 1

Yes, you are correct.

 

"sinusoid" means "shaped like the sin function".  If you see a graph of the sin function, you'll see that it goes up and down smoothly as x gets larger.

 

The cos function is actually the same shape, only shifted over horizontally.