Question

sinx+cosx>корень из 2

Answer 1

$sin(x)+cos(x)>sqrt2/*frac{sqrt2}{2}\frac{sqrt2}{2}sin(x)+frac{sqrt2}{2}cos(x)>1\sin(frac{pi}{4})sin(x)+cos(frac{pi}{4})cos(x)>1\cos(x-frac{pi}{4})>1\x-frac{pi}{4}>2pi n\x>frac{pi}{4}+2pi n$