What is the difference between 25i*20i/5i and 25i*20i/(5i) in CMPLX mode?

In summary, the conversation discussed the difference between two expressions involving complex numbers, specifically 25i*20i/5i and 25i*20i/5. The difference lies in the interpretation of the order of operations, with the former being interpreted as (25i*20i/5)i = (25i*20i/5)*i and the latter as (-500/5) * i. The importance of using parentheses to avoid ambiguity in expression evaluation was also mentioned.
  • #1
Nero26
21
1
Hi all,
This is a little problem I'm unable to figure out, in CMPLX mode of my calculator 25i*20i/5i=-100i
But 25i*20i/(5i) = 100i, Here i=sqrt(-1). What is the difference between these two expressions?
Thanks for your help.
 
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  • #2
The difference is that 25i*20i/5i is interpreted as (25i*20i/5)i = (25i*20i/5)*i.
And 25i*20i/5 = -100.
 
  • #3
CompuChip said:
The difference is that 25i*20i/5i is interpreted as (25i*20i/5)i = (25i*20i/5)*i.
And 25i*20i/5 = -100.

Thanks a lot for your help, so 'i' is considered as a single complex number.
 
  • #4
Nero26 said:
Thanks a lot for your help, so 'i' is considered as a single complex number.
Well, yes, but that's not relevant here.

What Compuchip was talking about was the order of operations. It's the difference between -500/(5i) and (-500/5) * i.

When you write (or enter) -500/5i, the calculator is interpreting this as -500/5 * i.
 
  • #5
In order to avoid ambiguity in expression evaluation, use parentheses in your expressions.
 
  • #6
Thanks to all. You all are of great help. I think I can learn a lot from PF.
 

FAQ: What is the difference between 25i*20i/5i and 25i*20i/(5i) in CMPLX mode?

What is a complex number?

A complex number is a number that contains both a real part and an imaginary part. It is written in the form a + bi, where a is the real part and bi is the imaginary part, with i being the square root of -1.

How do you add or subtract complex numbers?

To add or subtract complex numbers, you simply combine the real parts together and the imaginary parts together. For example, (3 + 4i) + (2 + 5i) = (3+2) + (4i+5i) = 5 + 9i. To subtract, you can distribute a negative sign and follow the same process.

How do you multiply complex numbers?

To multiply complex numbers, you can use the FOIL method as you would with binomials. For example, (3 + 4i)(2 + 5i) = 6 + 15i + 8i + 20i^2 = 6 + 23i - 20 = -14 + 23i.

How do you divide complex numbers?

To divide complex numbers, you can use the same process as dividing fractions. You multiply the numerator and denominator by the complex conjugate of the denominator. For example, (3 + 4i) / (2 + 5i) = (3 + 4i)(2 - 5i) / (2 + 5i)(2 - 5i) = (6 - 15i + 8i - 20i^2) / (4 + 25) = (-14 - 7i) / 29.

How do you use complex numbers in real life?

Complex numbers are used in many fields of science and engineering, such as in electrical engineering, quantum mechanics, and signal processing. They are also used in computer graphics and video game programming, as well as in solving various mathematical problems. In physics, complex numbers are used to describe phenomena that involve waves or oscillations, such as sound and light. They also have applications in economics, finance, and other social sciences.

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