The cofunction identity for cosine states that the cosine of an angle is equal to the sine of its complement. Specifically, this can be expressed as (\cos(t) = \sin\left(\frac{\pi}{2} - t\right)) in radians or (\cos(t) = \sin(90^\circ - t)) in degrees. This relationship highlights the complementary nature of the sine and cosine functions.
The cofunction of the complement of cos 89° is sin 1°. This is because the complement of 89° is 1° (90° - 89° = 1°), and the cofunction identity states that (\cos(θ) = \sin(90° - θ)). Therefore, (\cos(89°) = \sin(1°)).
cos(3t) = cos(2t + t) = cos(2t)*cos(t) - sin(2t)*sin(t) = [cos2(t) - sin2(t)]*cos(t) - 2*cos(t)*sin(t)*sin(t) = [cos2(t) - sin2(t)]*cos(t) - 2*cos(t)*sin2(t) then, since sin2(t) = 1 - cos2(t) = [2*cos2(t) - 1]*cos(t) - 2*cos(t)*[1 - cos2(t)] = 2*cos3(t) - cos(t) - 2*cos(t) + 2*cos3(t) = 4*cos3(t) - 3*cos(t)
Cos(360 - X) = Trig. Identity Cos(360)Cos(x) + Sin(360)Sin(x) => 1CosX + 0Sinx => CosX + o => CosX
sin^5 2x = 1/8 sin2x (cos(8x) - 4 cos(4x)+3)
The graph of the function ( f(t) = \sin(t) \cos(t) ) can be simplified using the double-angle identity for sine, resulting in ( f(t) = \frac{1}{2} \sin(2t) ). This function oscillates between -0.5 and 0.5, with a period of ( \pi ). The graph will exhibit a wave-like pattern, with peaks and troughs occurring at intervals of ( \frac{\pi}{2} ). Overall, it is a smooth, continuous curve that represents the amplitude-modulated sine wave.
The cofunction of the complement of cos 89° is sin 1°. This is because the complement of 89° is 1° (90° - 89° = 1°), and the cofunction identity states that (\cos(θ) = \sin(90° - θ)). Therefore, (\cos(89°) = \sin(1°)).
The cofunction of cosine is sine. Therefore, the cofunction of (\cos 70^\circ) is (\sin(90^\circ - 70^\circ)), which simplifies to (\sin 20^\circ). Thus, (\cos 70^\circ = \sin 20^\circ).
sec x - cos x = (sin x)(tan x) 1/cos x - cos x = Cofunction Identity, sec x = 1/cos x. (1-cos^2 x)/cos x = Subtract the fractions. (sin^2 x)/cos x = Pythagorean Identity, 1-cos^2 x = sin^2 x. sin x (sin x)/(cos x) = Factor out sin x. (sin x)(tan x) = (sin x)(tan x) Cofunction Identity, (sin x)/(cos x) = tan x.
cos 60
cos(3t) = cos(2t + t) = cos(2t)*cos(t) - sin(2t)*sin(t) = [cos2(t) - sin2(t)]*cos(t) - 2*cos(t)*sin(t)*sin(t) = [cos2(t) - sin2(t)]*cos(t) - 2*cos(t)*sin2(t) then, since sin2(t) = 1 - cos2(t) = [2*cos2(t) - 1]*cos(t) - 2*cos(t)*[1 - cos2(t)] = 2*cos3(t) - cos(t) - 2*cos(t) + 2*cos3(t) = 4*cos3(t) - 3*cos(t)
cos(t) - cos(t)*sin2(t) = cos(t)*[1 - sin2(t)] But [1 - sin2(t)] = cos2(t) So, the expression = cos(t)*cos2(t) = cos3(t)
The identity for tan(theta) is sin(theta)/cos(theta).
Case 1 -Frequency errorMultiplierMultiplierLow passfilterLow passfilter Message signalDSB-SCLocal oscillatorc(t)=Eccos([ct+([)Local oscillatorc(t)=Eccos([ct+([)Condition:Local oscillator has the samephasebutdifferentfrequencycompared to carrier signal at thetransmitter.[m2[c+[m2[c-[mLow pass filterhigh frequencyinformation)(cos]cos)([)([([[t t t mtycc)2(cos)(cos)()(cos)()2(cos)()(21212121[([[(![([([!t t t t t t tycc[(!cos)()(21t t v
Sine sum identity: sin (x + y) = (sin x)(cos y) + (cos x)(sin y)Sine difference identity: sin (x - y) = (sin x)(cos y) - (cos x)(sin y)Cosine sum identity: cos (x + y) = (cos x)(cos y) - (sin x)(sin y)Cosine difference identity: cos (x - y) = (cos x)(cos y) + (sin x)(sin y)Tangent sum identity: tan (x + y) = [(tan x) + (tan y)]/[1 - (tan x)(tan y)]Tangent difference identity: tan (x - y) = [(tan x) - (tan y)]/[1 + (tan x)(tan y)]
cos(x) = sin(pi/2 + x)
To show that (cos tan = sin) ??? Remember that tan = (sin/cos) When you substitute it for tan, cos tan = cos (sin/cos) = sin QED
Cos(360 - X) = Trig. Identity Cos(360)Cos(x) + Sin(360)Sin(x) => 1CosX + 0Sinx => CosX + o => CosX