Answer key for math question (1)

(a)

     (i) sin140⁰ = p

     (ii) cos70⁰ = −q

(b)

      Using sin²θ + cos²θ =1

      cos140⁰ = ±√1− p²

      cos140⁰ = − √1− p²

(c)

       tan140 ⁰ = sin140⁰/ cos140⁰

                         = -p / (√1− p²)