If Principal refers to the position at a school, the opposite would be Student. If it is in refference to a corporate position, the opposite would be a low ranking employee or a customer. If it is in refference to a Principal Sum or Balance, the opposite would be the closing sum or balance.
It highly depends on the context of the word Principal
Here are some possible opposites of interesting:uninterestingboringdulltiringtediousinterminable
Vice-principal
Opposition from the principal delayed the new school program.The issue of legalizing gay marriage has both extreme support and extreme opposition; few states have actually passed laws allowing it.
principal
This is your principal target. The principal goal must be achieved.
subtractive Principal actor.
The principal diagonals of all regular polygons.
A diagonal joining opposite angles is the principal diagonal. It may or may not bisect the angles, and that does not affect its name.
true
The principal quantum number describes the size of the orbital. Because they have opposite electrical charges, electrons MORE.
Pauli - it is the Pauli exclusion principal.
Here are some possible opposites of interesting:uninterestingboringdulltiringtediousinterminable
The opposite of a square root is the square of a number. For example, the principal square root of 81 is 9, while the square of 9 is 81.
If the "8 by 8 octagon" refers to the distances between its opposite sides rather than opposite vertices (its principal diagonals), then the side lengths are 8*[sqrt(2) - 1] units of length.
Vice-principal
Opposition from the principal delayed the new school program.The issue of legalizing gay marriage has both extreme support and extreme opposition; few states have actually passed laws allowing it.
The two square roots of a real number (other than 0) have the same value: one is the additive opposite of the other.So, the principal square root of 16 is 4. Then the other sqrt is -4.The principal sqrt of 2 is approx 1.424 and the other is -1.424.