Answer ঝ.` 1/(a - b - c) + 1/(a - b + c) + a/(a^2 + b^2 - c^2 - 2ab)`
`= (a - b + c + a - b - c)/((a - b - c) (a - b + c)) + a/(a^2 + b^2 - c^2 - 2ab)`
`= (2a - 2b)/((a - b)^2 - c^2) + a/(a^2 + b^2 - c^2 - 2ab)`
`= (2a - 2b)/(a^2 - 2ab + b^2 - c^2) + a/(a^2 + b^2 - c^2 - 2ab)`
`= (2a - 2b + a)/(a^2 - 2ab + b^2 + c^2)`
`= (3a - 2b)/(a^2 + b^2 - c^2 - 2ab)`
উত্তর: ` (3a - 2b)/(a^2 + b^2 - c^2 - 2ab)`
ঞ. `1/(a^2 + b^2 - c^2 + 2ab) + 1/(b^2 + c^2 - a^2 + 2bc) + 1/(c^2 + a^2 - b^2 + 2ca)`
`= 1/((a^2 + + 2ab + b^2) - c^2) + 1/((b^2 + 2bc + c^2) - a^2) `
`+ 1/((c^2 + 2ca + a^2) - b^2)`
`= 1/((a + b)^2 - c^2) + 1/((b + c)^2 - a^2) + 1/((c + a)^2 - b^2)`
`= 1/((a + b + c) (a + b - c)) + 1/((b + c + a) (b + c - a)) `
`+ 1/((c + a + b) (c + a - b))`
`= ((b + c - a) (c + a - b) + (a + b - c) (c + a - b) + (a + b - c) (b + c - a))/((a + b + c) (a + b - c) (b + c - a) (c + a - b))`
এখন লব, =
`bc + ab - b^2 + c^2 + ca - bc - ca - a^2 + ab + ca + a^2 - ab + bc + ab `
`- b^2 - c^2 - ca + bc + ab + ca - a^2 + b^2 + bc - ab - bc - c^2 + ca`
`= 2ca + 2bc + 2ab - b^2 - c^2 - a^2`
`= 2ab + 2bc + 2ca - a^2 - b^2 - c^2`
:. প্রদত্ত রাশি = `(2ab + 2bc + 2ca - a^2 - b^2 - c^2)/((a + b + c) (a + b - c) (b + c - a) (c + a - b))`
উত্তর: `(2ab + 2bc + 2ca - a^2 - b^2 - c^2)/((a + b + c) (a + b - c) (b + c - a) (c + a - b))`