Find the value of sin ⁡ π 10 − sin ⁡ 3 π 10

Question

Find the value of   sin  ⁡            π      10        −  sin  ⁡                    3        π            10

Schetterai · Accepted Answer

sin  ⁡            π      10        −  sin  ⁡                    3        π            10        =  cos  ⁡      72          ∘        +  cos  ⁡      144          ∘        =  =            2      sin      ⁡              36                  ∘                    cos      ⁡              72                  ∘                    +      2      sin      ⁡              36                  ∘                    cos      ⁡              144                  ∘                            2      sin      ⁡              36                  ∘                      =  =            sin      ⁡              108                  ∘                    −      sin      ⁡              36                  ∘                    +      sin      ⁡              180                  ∘                    −      sin      ⁡              108                  ∘                            2      sin      ⁡              36                  ∘                      =  −      1    2    .done!

Find the value of sin ⁡ π 10 − sin ⁡ 3 π 10

Answered question

Answer & Explanation