What's the difference between sin^2(x) and sin(x^2)?

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In summary, there is a difference between sin^2(x) and sin(x^2). The first expression is the product of sin(x) and itself, while the second expression is the square of sin(x). This can be confusing as sin2x is often used as a shorthand for (sin x)^2, but it is not a strictly logical notation and may not be recognized by calculators.
  • #1
bobsmith76
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Homework Statement



what's the difference between sin^2(x) and sin(x^2)?


Homework Equations





The Attempt at a Solution



I can't do sin^2(x) on the calculator. let's just use sin(25) as an example, what's the difference?
 
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  • #2
first expression is sin(x) times sin(x) so you'd enter it as ( sin(x) ) ^ 2 and your calculator should be able to evaluate it.
 
  • #3
[itex]sin^{2}x = sinxsinx [/itex]
The other 1 is just squaring the x not the whole function.Also on a side note,
[itex]sinx+sinx = 2sinx[/itex]
 
  • #4
bobsmith76 said:

Homework Statement



what's the difference between sin^2(x) and sin(x^2)?

The Attempt at a Solution



I can't do sin^2(x) on the calculator. let's just use sin(25) as an example, what's the difference?
Indeed. if x = 5, sin2(x) ≈ 0.919536, whereas sin(x2) ≈ -0.132352
 
  • #5
sin2x MEANS (sin x)2.

Which you can calculate on your calculator.

IMHO you are not the only one and not totally at fault to be confused - sin2x as far as I can see is a sort of mathematical slang, not strictly logical (so no wonder your calculator doesn't understand it either) which by its antiquity is let through and is universal - so there it is to get used to.
 

What is \( \sin^2(x) \)?

\( \sin^2(x) \) is a mathematical expression that represents the square of the sine of an angle \( x \). It means \( \sin(x) \) multiplied by itself. In other words, it's equivalent to \( (\sin(x))^2 \).

What is \( \sin(x^2) \)?

\( \sin(x^2) \) is a mathematical expression that represents the sine of the square of an angle \( x \). It means taking the sine of \( x \) squared, or \( \sin((x)^2) \).

What is the difference between the two?

The key difference lies in the order of operations. In \( \sin^2(x) \), you first find the sine of \( x \) and then square the result. In \( \sin(x^2) \), you first square \( x \) and then find the sine of the squared value.

Are the values of \( \sin^2(x) \) and \( \sin(x^2) \) the same?

No, the values of \( \sin^2(x) \) and \( \sin(x^2) \) are generally different. This is because squaring the sine of an angle and taking the sine of the squared angle produce different results, except in specific cases where \( \sin(x) = 0 \) or \( \sin(x) = \pm 1 \).

Can you provide an example to illustrate the difference?

Certainly! Let's take an example: If \( x = 30^\circ \) (or \( \frac{\pi}{6} \) radians), then \( \sin(30^\circ) = \frac{1}{2} \). Therefore, \( \sin^2(30^\circ) = \left(\frac{1}{2}\right)^2 = \frac{1}{4} \). On the other hand, \( \sin((30^\circ)^2) = \sin(900^\circ) = \sin(2\pi) = 0 \).

Are there specific applications for each of these expressions?

Yes, \( \sin^2(x) \) is often used in trigonometry and mathematics to represent the square of the sine function, which can be used in various mathematical calculations. \( \sin(x^2) \) may appear in more complex mathematical or scientific equations where the sine of a squared value is required.

Is there a common misconception about these expressions?

One common misconception is the incorrect use of notation. Some people may write \( \sin^2(x) \) when they mean \( (\sin(x))^2 \), and vice versa. It's important to understand the order of operations to use the correct notation and interpretation.

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