Unquestionable
Unquestionable, definite, not in question, beyond doubt, indubitable, irrefutable, incontrovertible, obvious, manifest, plain, transparent, unmistakable, recognized, accepted, undisputed, unquestioned, uncontested, as sure as eggs is eggs, bound, predestined, trusted, nailed on, assured, unavoidable, automatic, sure to happen, inexorable, predictable, out of one's hands, dependable, sound, tested, effective, guaranteed, infallible, sure-fire, sure, beyond question, not in doubt, unequivocal, undeniable, indisputable, incontestable, patent, evident, clear, palpable, conclusive, confirmed, acknowledged, undoubted, unchallenged, there are no two ways about it, very likely, destined, fated, assured of doing something, inevitable, reliable, inescapable, bound to happen, unpreventable, ineluctable, necessary, in the bag, trustworthy, foolproof, tried and tested, efficacious, unfailing, unerring, and sovereign.
Sure
Sure, positive, in no doubt, secure in one's belief, satisfied, persuaded, not question, confident, convinced, unshaken in one's belief, easy in one's mind, assured, have no doubt, and hold the unwavering view.
Determined
Determined, fixed, precise, exact, express, specific, special, definite, established, defined, explicit, particular, individual, and especial.