Q. Express as a complex number in simplest a+bi form:2+4i4−22iAnswer:
Multiply Numerators: To express the quotient (4−22i)/(2+4i) as a complex number in the form a+bi, we need to eliminate the imaginary unit i from the denominator. We do this by multiplying the numerator and the denominator by the complex conjugate of the denominator.The complex conjugate of (2+4i) is (2−4i).Now, multiply the numerator and the denominator by the complex conjugate of the denominator.(4−22i)/(2+4i)⋅(2−4i)/(2−4i)
Expand Numerator: First, multiply the numerators: (4−22i)∗(2−4i). Use the distributive property (FOIL method) to expand the product: 4⋅2+4⋅(−4i)−22i⋅2−22i⋅(−4i)=8−16i−44i+88i2 Since i2=−1, replace 88i2 with −88: =8−16i−44i−88 Combine like terms: =(8−88)+(−16i−44i)=−80−60i
Multiply Denominators: Next, multiply the denominators: (2+4i)∗(2−4i). Again, use the distributive property to expand the product: 2⋅2+2⋅(−4i)+4i⋅2−4i⋅4i = 4−8i+8i−16i2 Replace −16i2 with 16, since i2=−1: = 4+16 Combine like terms: = 20
Divide Numerator by Denominator: Now, divide the result from the numerators by the result from the denominators: (−80−60i)/20Divide both the real part and the imaginary part by 20:−80/20−(60i/20)=−4−3i
Final Complex Number: The complex number in the form a+bi is −4−3i. This is the simplest form of the given complex quotient.
More problems from Convert complex numbers between rectangular and polar form