How do you write the complex number #-3+4i# in polar form?

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Answer 1 · 2016-11-15T10:27:20

The polar form is #=5(cos126.9º+isin126.9º)#

Let #z=a+ib# a complex number

The polar form is #z=r(costheta+isintheta)#

#r=sqrt(a^2+b^2)#

Here, we have #z=-3+4i#

#:.r=sqrt(9+16)=sqrt25=5#

#z=5(-3/5+(4i)/5)#

#:.cos theta=-3/5# and #sintheta=4/5#

So, #theta# is in the second quadrant

#theta=126.9#º

#z=5(cos126.9º+isin126.9º)#