Explicație pas cu pas:
Folosim formula [tex] (a+b)^2=a^2+b^b+2ab [/tex].
[tex](\sqrt{1+sinx}+\sqrt{1-sinx})^2+(\sqrt{1+sinx}-\sqrt{1-sinx})^2=1+sinx+1-sinx+2\sqrt{1+sinx}\sqrt{1-sinx}+1+sinx+1-sinx-2\sqrt{1+sinx}\sqrt{1-sinx}=Reducem~termenii=1+1+1+1=4[/tex]
