Is sin-1(2i) Equal to 0.5 + 1.31696i?

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In summary, the conversation discusses the solution to the equation sin(x) = (exp(ix)-exp(-ix))/2i, specifically for the value of sin-1(2i). It is noted that the equation may have multiple solutions due to its quadratic nature and the use of logarithms in solving for y.
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symsane
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I could not found any answer to this question: What is sin-1(2i) equal?
 
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sin(x) = (exp(ix)-exp(-ix))/2i

Firstly let y=exp(ix) and subs in

( y + 1/y)/2i=2i

solve for y, then for x.
 
  • #3


Since you titled this thread "Multi-Valuedness", note that solving (y+ 1/y)/2i= 2i will involve solving a quadratic function so you may have two values for y. Then solving y= exp(ix) with both values of involves taking the logarithm which adds multiples of [itex]2\pi i[/itex].
 
  • #4


For the two last posts, isn't it supposed to be (y - 1/y)/2i = 2i ?
 
  • #5


Yes - I can't even seem to follow my own suggestion.
 

FAQ: Is sin-1(2i) Equal to 0.5 + 1.31696i?

What is sin-1(2i)?

The function sin-1(2i) is the inverse sine function, also known as arcsine, applied to the complex number 2i. It represents the angle in radians whose sine is equal to 2i.

Is sin-1(2i) a real number?

No, sin-1(2i) is not a real number because it involves the imaginary number i. It is a complex number with a real part of 0 and an imaginary part of ln(2+√5).

How do you calculate sin-1(2i)?

To calculate sin-1(2i), you can use the formula sin-1(z) = ln(iz + √(1-z^2)) where z is the complex number. In this case, z=2i. Plugging in the values, we get sin-1(2i) = ln(2i + √(1-4)) = ln(2i + √(-3)) = ln(2i + i√3).

What is the principal value of sin-1(2i)?

The principal value of sin-1(2i) is the principal branch of the inverse sine function, which is defined for complex numbers with a magnitude less than or equal to 1. Since 2i has a magnitude greater than 1, sin-1(2i) does not have a principal value.

What is the range of values for sin-1(2i)?

The range of values for sin-1(2i) is the set of all complex numbers, since the inverse sine function is defined for all complex numbers. However, as mentioned before, the principal value does not exist for this particular input. It is important to note that the range of values for inverse trigonometric functions may vary depending on the definition and conventions used.

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