Question

豬仔

請問是怎麼從BD:DC跟BE:EC的比例去算出ED的？
高二數學平面向量

9. 2 AB+ 3AČ = 5 AD ⇒ AD = ² AB+²³ĀC · B-D-C = BD : DC = 3: 2
2
3
5
4 PA = 7 PB+ 3PC ⇒ PA = PB+2 PC
2 __
7
3
²
10
10
7
3
✩ ²PÀ=PÈ = __ PB+² PC_B-E-C=BE: EC = 3:7 PA:PE=5:2
10
10
20: BD:DC=3:2 BE: EC = 3:7
BE:ED: DC = 3:3:4
LÉI† ABPC=50 LABC=30
AACD=12 AABP = 15
3.
A
E
3 3
C
2
B
C
P

向量