Consider the polynomials q(x) = x2 + 2x - 13 and r(x) = x3 - 3x. To plot the function (x) over (10,20] we use: a. fplot('x^2+2"x-13' [10 20]) b. q-sym(x^2+2*x-13) ezplot(q.[10 201) c. q=[12-13] x=10:0.1:20; y=polyval(p.x); plot(x,y) d. None of the above To calculate r(2), we use: a. r=[1 0 -3 0] polyval(r.2) b. Finline("x^3-3x) 1(2) c. syms x: r=x^3-3x subs(r.x.2) d all the above