Q. Express as a complex number in simplest a+bi form:2+i24−13iAnswer:
Multiply by Conjugate: Multiply the numerator and denominator by the conjugate of the denominator to remove the imaginary unit from the denominator.The conjugate of 2+i is 2−i.So, we multiply (24−13i)/(2+i) by (2−i)/(2−i) to rationalize the denominator.
Numerator Multiplication: Perform the multiplication in the numerator.Multiply (24−13i) by (2−i).Using the distributive property (FOIL method):24⋅2+24⋅(−i)−13i⋅2−13i⋅(−i)= 48−24i−26i+13i2Since i2=−1, replace 13i2 with −13.= 48−24i−26i−13= 48−13−(24i+26i)= 35−50i
Denominator Multiplication: Perform the multiplication in the denominator.Multiply (2+i) by (2−i).Using the difference of squares:2×2−i×2+i×2−i2=4−i2Since i2=−1, replace −i2 with 1.=4+1=5
Final Complex Number: Divide the results from Step 2 by the result from Step 3 to get the complex number in a+bi form.f(x)=535−50iDivide both the real part and the imaginary part by 5.=535−550i=7−10i
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