-->

Vector Algebra

Question
CBSEENMA12034097

If straight a with rightwards arrow on top is any vector, then show that
         straight a with rightwards arrow on top space equals space left parenthesis straight a with rightwards arrow on top space minus space straight i with hat on top right parenthesis space straight i with hat on top space plus space left parenthesis straight a with rightwards arrow on top. space straight j with hat on top right parenthesis space straight j with hat on top space plus space left parenthesis straight a with rightwards arrow on top space. space straight k with hat on top right parenthesis space straight k with hat on top.

Solution
straight a with hat on top space equals space straight a subscript 1 space straight i with hat on top space plus space straight a subscript 2 space straight j with hat on top space plus space straight a subscript 3 space straight k with hat on top                      ...(1)
      straight a with hat on top. space straight i with hat on top space equals straight a subscript 1 space straight i with hat on top. space straight i with hat on top space plus space straight a subscript 2 space straight j with hat on top space. space straight i with hat on top space plus space straight a subscript 3 space straight k with hat on top space. space straight i with hat on top space equals space straight a subscript 1 left parenthesis 1 right parenthesis space plus space straight a subscript 2 left parenthesis 0 right parenthesis space plus space straight a subscript 3 left parenthesis 0 right parenthesis
straight d with rightwards arrow on top space space straight i with hat on top space equals space straight a subscript 1
Similarly,  straight a with rightwards arrow on top. space straight j with hat on top space equals straight a subscript 2 comma space straight a with rightwards arrow on top space. straight k with hat on top space equals space straight a subscript 3
   from (1), we get
                           straight a with rightwards arrow on top space equals space left parenthesis straight a with rightwards arrow on top. space straight i with hat on top right parenthesis space straight i with hat on top space plus space left parenthesis straight a with rightwards arrow on top. space straight j with hat on top right parenthesis space straight j with hat on top space plus space left parenthesis straight a with rightwards arrow on top. space straight k with hat on top right parenthesis space straight k with hat on top