Tractable, a.
Etymology: [L. tractabilis, fr, tractare to draw violently, to handle, treat. See Treat, v. t.]
1. Capable of being easily led, taught, or managed; docile; manageable; governable; as, tractable children; a tractable learner. I shall find them tractable enough. Shak.
2. Capable of being handled; palpable; practicable; feasible; as, tractable measures. [Obs.] Holder. --Tract"a*ble*ness, n. -- Tract"a/bly, adv.
Shades of meaning
Fernald has no entry of its own for tractable; he lists it under docile.
Where he writes about it:
One who is docile is easily taught; one who is tractable is easily led; one who is pliant is easily bent in any direction; compliant represents one as inclined or persuaded to agreement with another's will. — from docile