Question

If A = 6î - 8ĵ, B = −8î + 3ĵandC = 26î + 19ĵ. Find a and b Such that aẢ +bB + C = 0
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Answer 1

Sol^n :

aA=6ai-8aj

bB=-8bi-3bj

C=26i-19j

Given aA+bB+C=0i+0j

(6a-8b+26)i-(8a+3b+19)j=0i+0j

comparing coefficient of i and j

6a-8b=-26

2a-4b=-13.....(1)

8a+3b=-19......(2)

making the coefficient of a similar

8a-16b=-52....(3)

8a+3b=-19....(4)

equation 4-3 implies

19b=33

b=33/19

from (1)

2a=-13+4(33/19)

2a=-115/19

a=-115/38