Q. A complex number z1 has a magnitude ∣z1∣=4 and an angle θ1=330∘.Express z1 in rectangular form, as z1=a+bi.Express a+bi in exact terms.z1=□
Conversion formula: To express a complex number in rectangular form, we use the polar to rectangular conversion formula, which is z=r(cos(θ)+isin(θ)), where r is the magnitude and θ is the angle in radians.
Convert angle to radians: First, we need to convert the angle from degrees to radians because the trigonometric functions in the formula require the angle to be in radians. The conversion is done by multiplying the degree measure by π/180. θ1 in radians = 330×(π/180)=(11/6)π
Calculate cosine and sine: Now we can calculate the cosine and sine of θ1 in radians.cos(θ1)=cos(611π) and sin(θ1)=sin(611π)
Substitute values into formula: Using the unit circle or trigonometric identities, we know that cos(611π)=cos(π−61π)=cos(65π)=−cos(61π) and sin(611π)=−sin(61π), since 611π is in the fourth quadrant where cosine is positive and sine is negative.
Simplify expression: The exact values for cos(61π) and sin(61π) are 3/2 and 1/2, respectively. Therefore, cos(611π) = −3/2 and sin(611π) = −1/2.
Simplify expression: The exact values for cos(61π) and sin(61π) are 3/2 and 1/2, respectively. Therefore, cos(611π)=−3/2 and sin(611π)=−1/2.Now we can substitute the values of r, cos(θ1), and sin(θ1) into the formula to get the rectangular form of z1.sin(61π)0
Simplify expression: The exact values for cos(61π) and sin(61π) are 3/2 and 1/2, respectively. Therefore, cos(611π)=−3/2 and sin(611π)=−1/2.Now we can substitute the values of r, cos(θ1), and sin(θ1) into the formula to get the rectangular form of z1.sin(61π)0Simplify the expression to get the final rectangular form of z1.sin(61π)2
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