WAEC - Mathematics (2017 - No. 31)
Given that t = \(2 ^{-x}\), find \(2 ^{x + 1}\) in terms of t.
\(\frac{2}{t}\)
\(\frac{t}{2}\)
\(\frac{1}{2t}\)
t
Vysvětlení
t = \(2^{-x} = \frac{1}{2^{x}}\)
\(\implies 2^{x} =\frac{1}{t}\)
\(2^{x+1} = 2^{x} \times 2^{1}\)
= \(\frac{1}{t} \times 2 = \frac{2}{t}\)