standard_description: Represent addition, subtraction, multiplication, and conjugation of complex numbers geometrically on the complex plane; use properties of this representation for computation. For example, (-1 + Ö3i)^(3) = 8 because (-1 + Ö3i) has modulus 2 and argument 120°.
problem_activity: Problem 1
Find
$${\mathrm{sin}(u-v)}$$
given
$${\mathrm{sin}(u)={8\over17}}$$
with
$${0\leq u \leq {\pi\over2}}$$
and
$${\mathrm{cos}(v)=-{24\over25}}$$
with
$${\pi \leq v \leq {3\pi\over2}}$$
.
Problem 2
Evaluate:
$${\mathrm{sin}(-15^{\circ})}$$
$${\mathrm{cos}(15^{\circ})}$$


aligns: no