How do you multiply #1.41(\cos 315^\circ + i \sin 315^\circ)#? Trigonometry The Polar System The Product and Quotient Theorems 1 Answer Wataru Oct 25, 2014 I assume that #1.41# is a decimal approximation of #sqrt{2}# here. #sqrt{2}(cos315^circ+i sin315^circ)=sqrt{2}(1/sqrt{2}-1/sqrt{2}i)=1-i# I hope that this was helpful. Answer link Related questions What is the quotient theorem of complex numbers in polar form? What is the product theorem of complex numbers in polar form? How do you use the product and/or quotient theorem of complex numbers in polar form to solve... What is the product of #3.61(\cos 56.3^\circ + i \sin 56.3^\circ)#? What is the product of #5 (cos frac{3\pi}{4}+isinfrac{3\pi}{4} ) \cdot... How do you find the quotient of #(\sqrt{3}-i) -: (2- 2\sqrt{3}i)#? See all questions in The Product and Quotient Theorems Impact of this question 2665 views around the world You can reuse this answer Creative Commons License