Bab 16 Ubahan

Posted on May 12, 2016 by user

5.1 Ubahan Langsung (Contoh Soalan)

Contoh 1:

Diberi bahawa p berubah secara langsung dengan punca kuasa dua q dan p=12 apabila q=36,cari

(a) nilai bagi p apabila q=16

(b) nilai bagi q apabila p=18

Penyelesaian:

$\begin{array}{l} p \propto \sqrt{q}, p = k \sqrt{q} \\ 12 = k \sqrt{36} \\ 12 = k (6) \\ k = 2 \\ p = 2 \sqrt{q} \end{array}$

$\begin{array}{l} (a) \\ p = 2 \sqrt{q} \\ p = 2 \sqrt{16} = 2 (4) \\ p = 8 \end{array}$

$\begin{array}{l} (b) \\ p = 2 \sqrt{q} \\ 18 = 2 \sqrt{q} \to 9 = \sqrt{q} \\ 9^{2} = q \\ q = 81 \end{array}$