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If a=hat(i)+hat(j)-2hat(k), b=2hat(i)-hat(j)+hat(k) and c=3hat(i)-hat(k) and c=ma+nb, then m+n is equal to |
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Answer» 0 `THEREFORE 3hati-hatk=m(hati+hatj-2hatk)+n(2hati-hatj+hatk)` `implies3hati-hatk=(m+2n)hati+(m-n)hatj+(-2m+n)hatk` On equationg the coefficients of `hati,hatj and hatk,` RESPECTIVELY, we get `3=m+2n,0=m-n` `and -1=-2m+n` `implies3=n+2n` `impliesn=1` `impliesm=1and n=1` ` impliesm+n=1+1=2` |
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