Ask them? :) No, seriously, the below answers are correct. I'm pretty sure the Santa Clara County recorder's office has a public site that you can check this on. Zillow -- and Trulia for that matter -- will also have it. Or, your friendly neighborhood Realtor -- myself, for example :) -- can check on it for you as well.
You can go to the Santa Clara County Recorder's office and if the sale (Title Transfer) has been recorded, you'll find the information you want. Otherwise, ask your Realtor and he/she will likely be able to find and provide you with more details than the sales price. Good Luck!
See if your County Recorder has an online data base of properties. If so, go there. If not, call a realtor in your town who has access to the Public Records of homes. Usually, new sales are listed within 30 days of being recorded. Liz