Prove $\sin ( \pi - x ) + \cos ( x - x ) = \sin x - \cos x$

Q18: Find all solutions of <span

Q19: Find the exact value. <span

Q20: Solve the given equation. <span

Q21: Find <span class="ql-formula" data-value="\sin 2

Q22: Solve the given equation. <span

Q24: Find the exact value. <span

Q25: Use a half-angle formula to find

Q26: Solve the given equation. <span

Q27: Write <span class="ql-formula" data-value="\cos x

Q28: Use the formula <span class="ql-formula"