Q. A complex number z1 has a magnitude ∣z1∣=5 and an angle θ1=150∘.Express z1 in rectangular form, as z1=a+bi.Express a+bi in exact terms.z1=□
Rectangular Form Expression: To express a complex number in rectangular form, we use the polar form of the complex number, which is z=r(cos(θ)+isin(θ)), where r is the magnitude and θ is the angle.
Substitute Values: Given ∣z1∣=5 and θ1=150 degrees, we can substitute these values into the polar form equation.z1=5(cos(150 degrees)+isin(150 degrees))
Calculate Cosine and Sine: We need to calculate the cosine and sine of 150 degrees. Since 150 degrees is in the second quadrant, we know that cosine will be negative and sine will be positive.cos(150 degrees)=cos(180 degrees−30 degrees)=−cos(30 degrees)sin(150 degrees)=sin(180 degrees−30 degrees)=sin(30 degrees)
Exact Trigonometric Values: We know the exact values for cos(30∘) and sin(30∘):cos(30∘)=23sin(30∘)=21
Substitute Exact Values: Substitute the exact values into the equation:z1=5(−3/2+i∗(1/2))
Distribute Magnitude: Now, distribute the magnitude (5) to both the real and imaginary parts:z1=5×−3/2+5×i×(1/2)
Simplify Expression: Simplify the expression: z1=−253+(25)i
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