Researchers from New Zealand have determined that the length of a brown trout depends on both its mass and age and that the length can be estimated by L(m, t) = (0.00082t + 0.0955)e^{(ln m+10.492/2.84)}, where L(m, t) is the length of the trout (in centimeters), m is the mass of the trout (in grams), and t is the age of the trout (in years).

(a) Find L(450, 4).
(b) Find L_m(450, 7) and L_t(450, 7) and interpret.