The minimum value of 27^cos x + 81^sin x is?
But with the large inequality, I don't know, maybe it can be equal.
No, because it's 3 to the power -5.@Moo: Minimum of 3 cos x + 4 sin x = - 5.
Gotta think about that thenThe answer is 1/4.
It's ok, I figured it out !
There is equality in AM GM if
So let m be the minimum value of , that is (substituting -5).
If , then
Thus m is the minimum, in particular when
Sounds more correct ?
Edit : I have to work it out deeper, because I assumed that 3cos(x)=4sin(x)