is algebraic, since it is (you check!) a root of the equation
One could say that there are "very few" algebraic numbers - technically they form a countable "measure-zero subset" of the real number line (or of the complex plane, if we speak about complex algebraic numbers). The transcendental numbers (whether real or complex) are precisely the numbers that are not algebraic. Here we can say just the opposite: "almost all" numbers are transcendental. Intuitively, if we imagine a point-like "shuttle" landing at random on some interval "planet" [a,b] with b > a , then the probability of the landing site being transcendental is 1. The tricky part is that even if "almost all" numbers are transcendental, it may be very hard to prove that a given number is transcendental! The study of transcendental numbers involves very sophisticated, elegant mathematics.