Mae indecsau’n ffordd o gynrychioli rhifau a llythrennau sydd wedi eu lluosi â’u hunain nifer o weithiau. Maen nhw’n ei gwneud yn haws i ni ddatrys problemau sy’n cynnwys pwerau.
Part ofMathemategRhif
Yr enwadur yw’r isradd.
Y rhifiadur yw’r pŵer.
\({a}^\frac{1}{2}\)
Felly, \({a}^\frac{1}{2} = (\sqrt{a})^{1}\)
\({8}^\frac{2}{3}\) = \((\sqrt[3]{8})^{2}\)
= 22
= 4
Felly, \({a}^\frac{n}{m} = (\sqrt[m]{a})^{n} = \sqrt[m]({a}^{n})\)
Enrhifa \({16}^\frac{1}{2}\)
\({16}^\frac{1}{2} = (\sqrt{16})\)
Enrhifa \({27}^\frac{2}{3}\)
\({27}^\frac{2}{3} = (\sqrt[3]{27})^{2}\)
= 32
= 9
\({a}^{n} \times {a}^{m} = {a}^{n+m}\)
\({a}^{n} ÷ {a}^{m} = {a}^{n-m}\)
\(({a}^{n})^{m} = {a}^{n \times m}\)
\({a}^{0} = {1}\)
\({a}^{-n} = \frac{1}{a^n}\)
\({a}^\frac{n}{m} = (\sqrt[m]{a})^{n} = \sqrt[m]({a}^{n})\)
