Having troubles (0.72∠-5π/36)/(1.38∠-17π/90)
They are complex numbers, or rather standard abbreviations for complex numbers.
0.72\(\angle (-5\pi/36)\) is a complex number with modulus 0.72 and argument \(-5\pi/36\).
The rule for division, (deduce it by writing the numbers in their cos + i.sin form), is divide the moduli and subtract the arguments.
So, for example \(12\angle(\pi/4)/2\angle(\pi/6)=6\angle(\pi/12).\)
Silly me, thank you :))
I would like more explanation of the division please :)
Put the numbers in their polar forms, \(r(\cos\theta+\imath\sin\theta)\), multiply top and bottom by the conjugate of the denominator and then, having multiplied out the brackets, use some standard trig identities to simplify.
I have to go out now, I'll get back to it later if it's still a problem.
yeah he raised the e^i theta to the power of negative 1 to get it on the numerator but forgot to do the same to r2.
Thanks for pointing out the mistake guys - I've now corrected it.