1.2指数形式& de Moivre定理

sin 7θ = 7 sinθ − 56 sin3 θ + 112 sin5 θ − 64 sin7 θ{"language":"en","fontFamily":"Times New Roman","fontSize":"18"}" class="Wirisformula" role="math" alt="罪恶空间7θ= 7空间sinθ-空间56罪立方空间θ+空间112空间罪恶的力量5空间θ- 64空间罪恶的力量7空间θ" style="vertical-align:-6px;height:23px;width:390px" loading="lazy">

1 + 7x − 56x3 + 112x5 − 64x7 = 0{"language":"en","fontFamily":"Times New Roman","fontSize":"18"}" class="Wirisformula" role="math" alt="1 + 7 x空间-空间56立方空间+ 112 x 64 x -空间的力量7空间等于0的力量" style="vertical-align:-6px;height:23px;width:277px" loading="lazy">

定义的无穷级数C和S

C = cos θ + 12 cos 5θ + 14 cos 9θ + 18 cos 13θ + ...{"language":"en","fontFamily":"Times New Roman","fontSize":"18"}" class="Wirisformula" role="math" alt="C空间= cosθ空间+ 1半空间因为空间5θ空间+ 1第四空间因为9θ空间+ 1 / 8 cosθ13空间+空间……" style="vertical-align:-17px;height:47px;width:405px" loading="lazy">

S = sin θ + 12 sin 5θ + 14 sin 9θ + 18 sin 13θ + ...{"language":"en","fontFamily":"Times New Roman","fontSize":"18"}" class="Wirisformula" role="math" alt="Sθ等于罪恶空间空间+ 1/2空间罪恶空间5θ+ 1第四空间罪恶空间9θ空间+ 1 / 8罪恶空间13θ+空间……" style="vertical-align:-17px;height:47px;width:391px" loading="lazy">

考虑到C和S系列都是收敛的,

C+iS=2eiθ2-e4iθ{"language":"en","fontFamily":"Times New Roman","fontSize":"18"}" class="Wirisformula" role="math" alt="连续C +直我S =分数分子2 e的力量直我θ指数除以分母2 - e的力量直4直我θ指数最终分数" style="vertical-align:-18px;height:49px;width:124px" loading="lazy">

S=4sinθ+2sin3θ5-4cos4θ{"language":"en","fontFamily":"Times New Roman","fontSize":"18"}" class="Wirisformula" role="math" alt="S =分数分子4 sinθ+ 2罪3θ/分母5 - 4 cosθ最终分数" style="vertical-align:-17px;height:47px;width:143px" loading="lazy">

在阿根图,点A{"language":"en","fontFamily":"Times New Roman","fontSize":"18"}" class="Wirisformula" role="math" alt="一个" style="vertical-align:-6px;height:22px;width:15px" loading="lazy">,B{"language":"en","fontFamily":"Times New Roman","fontSize":"18"}" class="Wirisformula" role="math" alt="B" style="vertical-align:-6px;height:22px;width:14px" loading="lazy">和C{"language":"en","fontFamily":"Times New Roman","fontSize":"18"}" class="Wirisformula" role="math" alt="C" style="vertical-align:-6px;height:22px;width:14px" loading="lazy">是一个等边三角形的顶点和中心在原点。这一点A{"language":"en","fontFamily":"Times New Roman","fontSize":"18"}" class="Wirisformula" role="math" alt="一个" style="vertical-align:-6px;height:22px;width:15px" loading="lazy">代表了复数6+2i{"language":"en","fontFamily":"Times New Roman","fontSize":"18"}" class="Wirisformula" role="math" alt="6 + 2直" style="vertical-align:-6px;height:22px;width:41px" loading="lazy">。

找到点所代表的复数B{"language":"en","fontFamily":"Times New Roman","fontSize":"18"}" class="Wirisformula" role="math" alt="B" style="vertical-align:-6px;height:22px;width:14px" loading="lazy">和C{"language":"en","fontFamily":"Times New Roman","fontSize":"18"}" class="Wirisformula" role="math" alt="C" style="vertical-align:-6px;height:22px;width:14px" loading="lazy">,给你的答案x+iy{"language":"en","fontFamily":"Times New Roman","fontSize":"18"}" class="Wirisformula" role="math" alt="我连续x + y" style="vertical-align:-6px;height:22px;width:43px" loading="lazy">,在那里x{"language":"en","fontFamily":"Times New Roman","fontSize":"18"}" class="Wirisformula" role="math" alt="x" style="vertical-align:-6px;height:22px;width:11px" loading="lazy">和y{"language":"en","fontFamily":"Times New Roman","fontSize":"18"}" class="Wirisformula" role="math" alt="y" style="vertical-align:-6px;height:22px;width:11px" loading="lazy">是真实的和准确的。

的点D{"language":"en","fontFamily":"Times New Roman","fontSize":"18"}" class="Wirisformula" role="math" alt="D" style="vertical-align:-6px;height:22px;width:15px" loading="lazy">,E{"language":"en","fontFamily":"Times New Roman","fontSize":"18"}" class="Wirisformula" role="math" alt="E" style="vertical-align:-6px;height:22px;width:13px" loading="lazy">和F{"language":"en","fontFamily":"Times New Roman","fontSize":"18"}" class="Wirisformula" role="math" alt="F" style="vertical-align:-6px;height:22px;width:12px" loading="lazy">的中点是三角形的吗ABC{"language":"en","fontFamily":"Times New Roman","fontSize":"18"}" class="Wirisformula" role="math" alt="A B C" style="vertical-align:-6px;height:22px;width:39px" loading="lazy">。

找到准确的三角形的面积DEF{"language":"en","fontFamily":"Times New Roman","fontSize":"18"}" class="Wirisformula" role="math" alt="D E F" style="vertical-align:-6px;height:22px;width:36px" loading="lazy">。