Practicing Success
If a + b = \(\frac{3}{4}\) and ab = \(\frac{1}{8}\), then find a4 + b4 + ab3 + ba3. |
\(\frac{27}{128}\) \(\frac{9}{256}\) \(\frac{27}{256}\) \(\frac{9}{64}\) |
\(\frac{27}{256}\) |
a + b = \(\frac{3}{4}\) Squaring both sides a2 + b2 + 2ab = \(\frac{9}{16}\) a2 + b2 = \(\frac{9}{16}\) - 2 × \(\frac{1}{8}\) a2 + b2 = \(\frac{5}{16}\) Squaring both sides again in equation a4 + b4 = \(\frac{25}{256}\) - 2a2b2 a4 + b4 = \(\frac{25}{256}\) - 2 × \(\frac{1}{64}\) a4 + b4 = \(\frac{17}{256}\) ⇒ Put the value in below equation ⇒ a4 + b4 + ab (a2 + b2) = \(\frac{17}{256}\) + \(\frac{5}{128}\) = \(\frac{27}{256}\) |