题库网
#91fbf729-df06-495a-9101-2bb44614ed73基础解答题二倍角公式三角函数与三角恒等变换

4. (2023春•淮安区月考)计算求值:
(1)sin15cos5sin20cos15cos5cos20\frac{\sin 1{5}\circ \cos {5}\circ -\sin 2{0}\circ }{\cos 1{5}\circ \cos {5}\circ -\cos 2{0}\circ }
(2)(cos220sin220)(1+3tan10)(co{s}^{2}2{0}\circ -si{n}^{2}2{0}\circ )(1+\sqrt{3}\tan 1{0}\circ )