Question Number 81498 by jagoll last updated on 13/Feb/20
$$\mathrm{what}\:\mathrm{the}\:\mathrm{formula} \\ $$$$\bar {\mathrm{a}}\:×\:\left(\bar {\mathrm{b}}×\bar {\mathrm{c}}\right)\:? \\ $$
Answered by TANMAY PANACEA last updated on 13/Feb/20
$$\left(\overset{\rightarrow} {{a}}.\overset{\rightarrow} {{c}}\right)\overset{\rightarrow} {{b}}−\left(\overset{\rightarrow} {{a}}.\overset{\rightarrow} {{b}}\right)\overset{\rightarrow} {{c}} \\ $$$${Tanmay}\: \\ $$
Commented by jagoll last updated on 13/Feb/20
$$\mathrm{thank}\:\mathrm{you}\:\mathrm{mister} \\ $$
Commented by jagoll last updated on 13/Feb/20
$$\mathrm{i}'\mathrm{m}\:\mathrm{forgot}\:\mathrm{this}\:\mathrm{formula} \\ $$
Commented by mr W last updated on 13/Feb/20
$${and}\:\left(\boldsymbol{{a}}×\boldsymbol{{b}}\right)×\boldsymbol{{c}}=? \\ $$
Commented by TANMAY PANACEA last updated on 13/Feb/20
$$−\overset{\rightarrow} {{c}}×\left(\overset{\rightarrow} {{a}}×\overset{\rightarrow} {{b}}\right) \\ $$$$=\left(−\overset{\rightarrow} {{c}}.\overset{\rightarrow} {{b}}\right)\overset{\rightarrow} {{a}}−\left(−\overset{\rightarrow} {{c}}.\overset{\rightarrow} {{a}}\right)\overset{\rightarrow} {{b}} \\ $$$$=−\left(\overset{\rightarrow} {{c}}.\overset{\rightarrow} {{b}}\right)\overset{\rightarrow} {{a}}+\left(\overset{\rightarrow} {{c}}.\overset{\rightarrow} {{a}}\right)\overset{\rightarrow} {{b}} \\ $$$$=\left(\overset{\rightarrow} {{c}}.\overset{\rightarrow} {{a}}\right)\overset{\rightarrow} {{b}}−\left(\overset{\rightarrow} {{c}}.\overset{\rightarrow} {{b}}\right)\overset{\rightarrow} {{a}} \\ $$$${pls}\:{check} \\ $$
Commented by mr W last updated on 13/Feb/20
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Commented by TANMAY PANACEA last updated on 13/Feb/20
$${thank}\:{you}\:{sir} \\ $$