SOLUTION: hai i am doing B.Sc(maths) Ist year at madurai kamaraj university in correspondence. this question is from trigonometry, complex numbers find the modulus and amplidude form

Question 56685: hai
i am doing B.Sc(maths) Ist year at madurai kamaraj university in correspondence.
this question is from trigonometry, complex numbers
find the modulus and amplidude form of (1-i)(1-2i)/(1+3i)
i have tried this one
(1-i)(1-2i)/(1+3i) = (1-i)(1-2i)(1+3i)/(1-3i)(1+3i)(multiplyingnumerator & dinominator by the conjugate)
=(8+6i^3)/10
(1-i)(1-2i)/(1+3i) =(4-3i)/5
r=square root(x^2+y^2)
=square root ((4/5)^2+(-3/5)^2)
r=square root (1)
cos theta=x/r
=4/5 square root (1)
sin theta=y/r
=-3/5 square root(1)

Answer by venugopalramana(3286) (Show Source): You can put this solution on YOUR website!

SEE MY COMMENTS BELOW
hai
i am doing B.Sc(maths) Ist year at madurai kamaraj university in correspondence.
this question is from trigonometry, complex numbers
find the modulus and amplidude form of (1-i)(1-2i)/(1+3i)
i have tried this one
(1-i)(1-2i)/(1+3i) = (1-i)(1-2i)(1+3i)/(1-3i)(1+3i)(multiplyingnumerator & dinominator by the conjugate) ......GOOD
=(8+6i^3)/10.........................VERY GOOD
(1-i)(1-2i)/(1+3i) =(4-3i)/5 ..OK..BUT SIMPLER IS 8+6I^3=8+6I*I^2=8-6I=2(4-3I)
r=square root(x^2+y^2)...............GOOD
=square root ((4/5)^2+(-3/5)^2).................GOOD
r=square root (1) =OK.....PUT IT AS = 1
cos theta=x/r...NO WHY?
PUT TAN THETA = -3/4 AND THETA = ARC TAN(-3/4) IS THE AMPLITUDE
WELL ONE KEEP IT UP..YOU NEED JUST A LITTLE BRUSHING UP..
=4/5 square root (1)
sin theta=y/r
=-3/5 square root(1)

RELATED QUESTIONS
sir, i am doing B.Sc(maths) 1st year at madurai kamaraj university through distance... (answered by stanbon)

hello sir, this is question of upbte maths examination of ist year,2015 my question... (answered by Fombitz)

I am 62 and am tutoring a 50-year old woman who needs to pass the entrance exam for a... (answered by Theo,lwsshak3)

Hi, i am in year 12 maths B and don't understand how to use logarithms at all. An example (answered by Alan3354)

Hi, I am trying to complete an exam question on Further Maths Trigonometry. I have found... (answered by stanbon)

i am very bad at maths and i am preparing for waec this year please can you help me... (answered by MathLover1)

An accounting firm in a college town usually recruits employees from two of the... (answered by solver91311)

The student population at a university dropped from 8,500 to 7395 in one year. Determine... (answered by rfer)

You have borrowed $200000 at 7% p.a taken over 25 years a)How much is the standard... (answered by xcentaur)