a Symmetrical triangular function with positive and negative values

Question

does there a Symmetrical triangular function which has positive value in the first and second quarters and negative value in the third and forth quarters?

Answer 1

sin θ ≥ 0, for 0 ≤ θ ≤ π

sin θ ≤ 0, π ≤ θ ≤ 2π