Draw a parallel line of alternating current, pass through point F, and intersect with BE at point G.
1∴⊿BFG∽⊿BAE。
∴FG:AE=BG:BE=BF:BA=2:3.
AE = EC .
∴FG:CE=2:3.
2∵⊿FGP∽⊿CEP and FG: CE = 2: 3.
∴ FP: CP = GP = EP = 2: 3。 ∴ CP: CF = 3: 5。 That is CP = (3/5) cf.
Then BG: ge = BF: fa = 2: 1 (parallel lines are proportional)
And gp: EP = 2 ∶ 3 means BP: be = 12: 15 = 4/5.
∴BP=(4/5)BE.
∴ To sum up, as vectors, there are: BP=(4/5)BE, and CP = (3/5) CF.
3 (all the following are vectors)
According to the triangle rule of vector addition, BE+EA=BA.
∴be=ba-ea=(-ab)-(-ae)=-ab+ae=-a+( 1/2)b.
That is, the vector BE=-a+( 1/2)b and the vector BP=(4/5)BE.
∴ Vector BP = (-4/5) A+(2/5) B.
According to the triangle rule of vector addition, CF+FA=CA.
∴ vector cf = ca-fa = (-AC)-(-af) =-b+af =-b+(1/3) ab = (1/3) a-b.
That is, the vector CF=( 1/3)a-b and the vector CP = (3/5) cf.
∴ vector CP = (1/5) A-(3/5) B