Evaluate ∫₀π/³​​r(t)dt given r(t)=⟨2/3​cost,sec​​²t⟩
O ⟨−√3​,√3/3​​⟩
O ⟨√3​,√3/3​​⟩
O ⟨−√3/3​​,√3​⟩
O ⟨−√3/3​​,√3​⟩