Practicing Success
If 2\(\sqrt {2}{x}^{3}\) - 3\(\sqrt {3}{y}^{3}\) = (\(\sqrt {2}x\) - \(\sqrt {3}y\)) (Ax2 + By2 + Cxy) find the value of (A2 + B2 + C2) |
4 9 19 7 |
19 |
⇒ a³ - b³ = (a-b) (a2 + b2 + ab) ⇒ 2\(\sqrt {2}{x}^{3}\) - 3\(\sqrt {3}{y}^{3}\) = (\(\sqrt {2}x\) - \(\sqrt {3}y\)) (Ax2 + By2 + Cxy) ............(i) ⇒ (\(\sqrt {2}{x})^{3}\) - (\(\sqrt {3}{y})^{3}\) = (\(\sqrt {2}x\) - \(\sqrt {3}y\)) ((\(\sqrt {2}\)x)2 + (\(\sqrt {3}\)y)2 + \(\sqrt {3×2}\)xy) ........(ii) Comparing (i) and (ii) So, A = (\(\sqrt {2}\))2 = 2 B = (\(\sqrt {3}\))2 = 3 C = \(\sqrt {6}\) ⇒ A2 +B2 +C2 = 4 + 9 + 6 = 19 |