9876543210
everything's fuzzy..
a,b,c,d are positive real numbers, each strictly less than pie/2.
i) Show that cos a cos b< or = {cos 1/2 (a+b)}^2
ii) Hence show that cosa cosb cosc cosd < or = {cos 1/4 (a+b+c+d)}^4
i cant solve the second part.
thx!=D
i) Show that cos a cos b< or = {cos 1/2 (a+b)}^2
ii) Hence show that cosa cosb cosc cosd < or = {cos 1/4 (a+b+c+d)}^4
i cant solve the second part.
thx!=D