To find the conjugate of ( \cos z ) for a complex number ( z = x + iy ) (where ( x ) and ( y ) are real numbers), you can use the formula for the cosine of a complex argument:
[ \cos z = \cos(x + iy) = \cos x \cosh y - i \sin x \sinh y. ]
The conjugate of ( \cos z ) is obtained by taking the complex conjugate of the expression, resulting in:
[ \overline{\cos z} = \cos x \cosh y + i \sin x \sinh y. ]
Given a complex number z = a + bi, the conjugate z* = a - bi, so z + z*= a + bi + a - bi = 2*a. Note that a and b are both real numbers, and i is the imaginary unit: +sqrt(-1).
cos(195) = -0.965925826289
To find the cosine of an angle in degrees using a calculator, first ensure that the calculator is set to degree mode (not radians). Enter the angle in degrees, then press the "cos" button. The calculator will display the cosine value for that angle. For example, to find cos(60°), input 60, select "cos," and the result will be 0.5.
A Quadrantal angle is an angle that is not in Quadrant I. Consider angle 120. You want to find cos(120) . 120 lies in quadrant II. Also, 120=180-60. So, it is enough to find cos(60) and put the proper sign. cos(60)=1/2. Cosine is negative in quadrant II, Therefore, cos(120) = -1/2.
cos(30)cos(55)+sin(30)sin(55)=cos(30-55) = cos(-25)=cos(25) Note: cos(a)=cos(-a) for any angle 'a'. cos(a)cos(b)+sin(a)sin(b)=cos(a-b) for any 'a' and 'b'.
To find the multiplicative inverse of a complex number z = (a + bi), divide its complex conjugate z* = (a - bi) by z* multiplied by z (and simplify): z = 4 + i z* = 4 - i multiplicative inverse of z: z* / (z*z) = (4 - i) / ((4 - i)(4 + i) = (4 - i) / (16 + 1) = (4- i) / 17 = 1/17 (4 - i)
y = sin6(z) dy/dz = 6*sin5(z)*cos(z) then d2y/dz2 = 6*5*sin4(z)*cos(z) + 6*sin5(z)*(-sin(z)) = 6*sin4(z)*[5*cos(z) - sin2(z)]
If z = a + ib then arg(z) = arctan(b/a) Let z' denote the conjugate of z. Therefore, z' = a - ib Then arg(z') = arctan(-b/a) = 2*pi - arctan(b/a) = 2*pi - arg(z)
Given a complex number z = a + bi, the conjugate z* = a - bi, so z + z*= a + bi + a - bi = 2*a. Note that a and b are both real numbers, and i is the imaginary unit: +sqrt(-1).
Yes, the difference between a complex number and its conjugate is a pure imaginary number. If we represent a complex number as ( z = a + bi ) (where ( a ) is the real part and ( b ) is the imaginary part), its conjugate is ( \overline{z} = a - bi ). The difference ( z - \overline{z} = (a + bi) - (a - bi) = 2bi ), which is purely imaginary since it has no real part.
Problem: find three solutions to z^3=-1. DeMoivre's theorem is that (cos b + i sin b)^n = cos bn + i sin bn So we can set z= (cos b + i sin b), n = 3 cos bn + i sin bn = -1. From the last equation, we know that cos bn = -1, and sin bn = 0. Three possible solutions are bn=pi, bn=3pi, bn=5pi. This gives three possible values of b: b=pi/3 b=pi b = 5pi/3. Now using z= (cos b + i sin b), we can get three possible cube roots of -1: z= (cos pi/3 + i sin pi/3), z= (cos pi + i sin pi), z= (cos 5pi/3 + i sin 5pi/3). Working these out gives -1/2+i*sqrt(3)/2 -1 -1/2-i*sqrt(3)/2
3 - 3i Let's try to represent the given complex number in the polar form. z = |z|(cos θ + i sin θ) let z = 3 - 3i in the form a + bi, where a = |z|cos θ and b = |z| sin θ so that |z| = √(a2 + b2) = √[(3)2 + (- 3)2] = √(9 + 9) = √18 = 3/√2 cos θ = a/|z| = 3/3√2 = 1/√2 and sin θ = b/|z| = -3/3√2 = -1/√2 z = 3 - 3i = |z|(cos θ + i sin θ) =3√2(1/√2 - i 1/√2)
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For example, the conjugate of 5 + 3i is 5 - 3i. The graph of the first number is three units above the real number line; the second one is three units below the real number line.
The complex conjugate of a+bi is a-bi. This is written as z* where z is a complex number. ex. z = a+bi z* = a-bi r = 3+12i r* = 3-12i s = 5-6i s* = 5+6i t = -3+7i = 7i-3 t* = -3-7i = -(3+7i)
Let the sides be x, y, z. Let the angles opposite those sides be X, Y, Z You can use the Cosine Law which states cos X = (y^2 + z^2 - x^2)/2yz Then calculate cos^-1(or arccos X) and this will give you the angle in degrees. then do the same for Y cos Y = (x^2 + z^2 - y^2)/2xz Do the same to get Y. Then add X and Y and subtract for 180° and you have your three angles.
To find the complex conjugate of a number, change the sign in front of the imaginary part. Thus, the complex conjugate of 14 + 12i is simply 14 - 12i.