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2V3 -12VS + 2fx=çŚ2 and y=75-2v5-2: find :(ii) y2 |
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Answer» If x = root(5) - 2/root(5) + 2 Rationalise x = (root(5) - 2)^2 / 5 - 4 = (root(5) - 2)^2 = 5 + 4 - 4 root(5) = 9 - 4root(5) (i) x^2 = (9 - 4 root (5))^2 = 81 + 16*5 - 72 root (5) = 161 - 72 root (5) If y = root(5) + 2/root(5) - 2 Rationalise y = (root(5) + 2)^2 / 5 - 4 = (root(5) + 2)^2 = 5 + 4 + 4 root(5) = 9 + 4root(5) (i) y^2 = (9 + 4 root (5))^2 = 81 + 16*5 + 72 root (5) = 161 + 72 root (5) |
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