Math question of the week (1)

Let p=sin40⁰ and q=cos110⁰. Give your answers to the following in terms of p and/or q

(a) Write down an expression for 

      1. sin140⁰ 

      2. cos110⁰

(b) Find an expression for cos140⁰.

(c) Find an expression for tan140⁰.