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- Oct 1st 2007, 05:51 AMafeasfaerw23231233vectors question #4
- Oct 1st 2007, 06:58 AMtopsquark
- Oct 1st 2007, 07:41 AMafeasfaerw23231233
i cannot find the value of 'lambda'

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my question is here

- Oct 1st 2007, 07:49 AMafeasfaerw23231233
- Oct 1st 2007, 09:25 AMtopsquark
- Oct 1st 2007, 09:39 AMtopsquark
a)

OC = OA + AC = a + 2b

BC = BO + OC = (-b) + (a + 2b) = a + b

OQ = OB + BQ = OB + (1/3)BC = b + (1/3)(a + b) = (1/3)a + (4/3)b

b)

i) OR = OP + PR = (1/2)OA + hPQ

Now, PQ = PO + OQ = -(1/2)OA + OQ = -(1/2)a + (1/3)a + (4/3)b = -(1/6)a + (4/3)b

So

OR = (1/2)OA + hPQ = (1/2)a + h[-(1/6)a + (4/3)b]

(I'll let you simplify that.)

ii)

OR = k OC

(1/2)a + h[-(1/6)a + (4/3)b] = k[a + 2b]

From here equate the coefficients of a on each side of the equation and the coefficients of b on each side of the equation. Two equations in two unknowns, h and k, so you can solve this.

I have to go. See if you can carry on from here.

-Dan