Which of the following is equivalent to sin^2(x) for all x?

Question

Which of the following is equivalent to sin^2(x) for all x? Select all that apply.

1) sin(sinx)
2) 2sinx
3) (sinx)^2
4) sin(2x)
5)sinx^2

I tried doing the 1st and third one but I got it wrong. please help me, I don't understand.

Answer 1

Hi Dhiradj,

 

The question is asking what is equivalent to sine squared X.  This means that you are finding the sine of an angle and then squaring that value.  For example, if the angle is 30 degrees, the sine is 1/2 so sine squared of 30 is 1/2 x 1/2 = 1/4.

 

The only choice that is equivalent is choice (3) which takes the sine of the angle and then squares it.

 

Dan

Answer 2

Dhiradj

 

Sin²(x) = Sin(x) Sin(x)

 

This is the same as 

[Sin(x)]²

 

The answer is #3.

 

1 is incorrect because an x is missing

5 is incorrect because it's squaring the x, not the sin(x)

2 and 4 are also incorrect.