(23 points! ) use the identity sina-sinb = 2sin((a-b)/2)cos((a+b)/2) to find lim x--> 1 f(x)=(sinx-sin1)/(x-1)
answer is cos1

Tamar is measuring the sides and angles of tuv to determine whether it is congruent to the triangle below. which pair of measurements would eliminate the possibility that the triangles are congruent