How do you express the complex number in trigonometric form: 3? Precalculus Complex Numbers in Trigonometric Form Trigonometric Form of Complex Numbers 1 Answer Shwetank Mauria Jun 27, 2016 #3# is written as #3cos0+isin0# or #3e^(i0)# Explanation: A number #a+ib# is written as #rcostheta+irsintheta# or #re^(itheta)# in polar form, where #r=sqrt(a^2+b^2)# and #tantheta=b/a# As #3=3+i0#, #r=sqrt(3^2+0^)=sqrt9=3# and as #tantheta=0/3=0#, #theta=0# Hence #3# is written as #3cos0+isin0# or #3e^(i0)# Answer link Related questions How do I find the trigonometric form of the complex number #-1-isqrt3#? How do I find the trigonometric form of the complex number #3i#? How do I find the trigonometric form of the complex number #3-3sqrt3 i#? How do I find the trigonometric form of the complex number #sqrt3 -i#? How do I find the trigonometric form of the complex number #3-4i#? How do I convert the polar coordinates #3(cos 210^circ +i\ sin 210^circ)# into rectangular form? What is the modulus of the complex number #z=3+3i#? What is DeMoivre's theorem? How do you find a trigonometric form of a complex number? Why do you need to find the trigonometric form of a complex number? See all questions in Trigonometric Form of Complex Numbers Impact of this question 8675 views around the world You can reuse this answer Creative Commons License