- Thread starter Indranil
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This is not correct.… sin.sin = sin² …

'sin' is not a number, so you may not square it.

'sin' is a name. It refers to the Sine function.

Have you learned about function notation? If not, now is the time to google it and learn (i.e., before you study trigonometry).

Sine is one of the six trigonometric functions. We input an angle measurement (call it x) into the sine function, and the function outputs the angle's sine value.

sin(x) is function notation for the output.

Therefore, the notation sin²(x) means the square of the number sin(x).

sin²(x) = sin(x) ⋅ sin(x)

For example, the sine of 30° is 1/2. In other words, if we input 30° into the sine function, the output is 1/2.

sin(30°) = 1/2

sin²(30°) = (1/2)(1/2) = 1/4 :cool:

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sin has no meaning at all, so sin*sin has no meaning.As we know x.x = x²,so sin.sin = sin² but, Why sinx.sinx = sin²x not sin²x²? Please explain.

Think of f(x) and just writing f. It has no meaning. You can find/calculate f(x), f(2), f(7.897); but not f. Similarly you can calculate sin(x) or sin(2pi/3), but you can't compute sin.

It seems that you think that sin x = sin*x which is NOT true. sin(x)*sin(x) = (sin(x))

I am very glad that you asked this question as you really need to understand why what you said was wrong. If you have any questions about this please reply to the post.

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It's important to understand that sin²x is a special notation that is inconsistent with other notations, and is defined to mean (sin x)As we know x.x = x²,so sin.sin = sin² but, Why sinx.sinx = sin²x not sin²x²? Please explain.

In fact, for other functions, the notation f

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