The leading term is the term with #x# raised to the highest exponent, in this case it's #-3x^2#. The degree is the highest power #x# is raised to, in this case 2, the leading coefficient is the coefficient or the constant part of the leading term, #-3#. The constant term is the term that is not multiplied by #x#, #4#, and since this is a concave down parabola (all degree two polynomials are parabolas and the leading coefficient is negative, thus concave down), you know that as #x# goes to infinity, so does #f(x)#.