Question #ac2da

1 Answer
Aug 10, 2016

No such thetaθ exists.

Explanation:

It is an identity that cos^2(theta) + sin^2(theta) = 1cos2(θ)+sin2(θ)=1 for all thetaθ, thus no thetaθ will result in the given equality.


In the real numbers, there is also the reasoning that
-1<=cos(theta)<=11cos(θ)1 and -1<=sin(theta)<=11sin(θ)1
=>
0 <= cos^2(theta) <= 10cos2(θ)1 and 0<=sin^2(theta)<=10sin2(θ)1.

Then, even if we allow different angles, for any theta, gamma in RR (the real numbers):

cos^2(theta)+sin^2(gamma) <= 1+1 = 2


Even if we allow for complex arguments, however, which allow for greater values of sine and cosine, the original identity still holds, meaning there is still no theta fulfilling cos^2(theta)+sin^2(theta)=3.