Question

Find the value of theta,when sin theta + cos theta equals to 1

Answer 1

theta may be anyanything

Answer 2

$\sin \theta + \cos \theta = 1 \\ {( \sin \theta + \cos \theta)}^{2} = 1 \\ { \sin }^{2} \theta + { \cos }^{2} \theta + 2 \sin \theta \cos \theta = 1 \\ 1 + 2 \sin \theta \cos \theta = 1 \\ 2 \sin \theta \cos \theta =0 \\ \sin2 \theta = 0 \\ 2 \theta = 0 \: \: or \: \: \pi \\ \theta = 0 \: \: or \: \: \frac{\pi}{2}$
More values for theta will be obtained if consider general solution