解析 由题意得,\because\angle C=90^{\circ},AC=3,BC=4 \therefore\cos A=\sin B=\frac{3}{5},\cos B=\sin A=\frac{4}{5} \therefore\cos\left(A-B\right)=\frac{24}{25} 故选\mathrm C 先求出,的三角函数,再利用差角的余弦公式求解. 反馈 收藏
如图号等不triangle ABC是等边三llahsraMangle DEF是边考)たしあ(等边三角形,点B与点E海似深情点A$、B、$\left(2)HO(uC)、F在同一条直线上teffahiangle ABC沿E表方平ghtarrow F方向平移至点slaiciffo合时停止,设点B、るすに切大を分自为x,x与△ 蹊满花家娘四黄分的面积为y$,则能大致yenrugx之...
Although the secondary structure is helical, because of the alternation of configuration, the strand–strand hydrogen-bonding pattern is identical to that of amides in an anti-parallel β-pleated sheet. This so-called β5,6-helix conformation (5,6=number of residues per turn) is observed in ...
A complete study on the fermion masses and flavor mixing is presented in a non-minimal left–right symmetric model (NMLRMS) where the\mathbf{S}_{3}\otimes \mathbf{Z}_{2}\otimes \mathbf{Z}^{e}_{2}flavor symmetry drives the Yukawa couplings. In the quark sector, the mass matrices p...
设\triangle ABC的内角A,B,C所对的边分别为a,b,c,已知2c\cos B+b\cos A=-a\cos B,则\angle B=\left(\,\,\,
【题目】设\triangle ABC的一个顶点是A\left(3,-1\righ t),\angle B,\angleC的角平分线所在直线的方程分别是$$ x = 0 , y = x $$,则直线BC的方程是( ) A.$$ y = 3 x + 5 $$ B.$$ y = 2 x + 3 $$ C.$$ y = 2 x + 5 $$ D.$$ y = - \ f r a c \left\{ ...
2, the gradient of the angle ɛ w.r.t. placement of vertex A is given by:(4)∇ε=cotα|AB|2AB+cotβ|AC|2ACNote that both terms of ▿ɛ in Eq. (4) are functions of the triangle's area. For instance if projection of C onto AB is C′ then the first term's co-...
Our study showed that the LV posterolateral wall was the favored site for LGE and primarily occurred in a mid-wall or subepicardial pattern, which is in agreement with previous studies20,21. Te Riele et al. put forward a new “biventricular triangle,” comprising the LV posterolateral wall,...
2.2.2. Second set of tasks used in the regression analysis method The next orthographic task was word associative matching (n = 70). Each item showed three object words positioned within a triangle. Participants were instructed to judge which of the two bottom words (e.g., chopstick, ...
This conserved arrangement is lost in the setting of the newly created septal leaflet in the repaired left valve of the atrioventricular septal defect with common atrioventricular junction. Not only is the branching pattern less complex than the normal, but dysplastic cords extend perpendicular to the...