Question

Given E = I × R and P = E × I, select the formula that will solve for E when only R and P are known.

Answer 1

E =IR

P = EI

solve for I by dividing both sides by E

P/E = I

E = IR

substitute for I

E = (P/E) *R

Multiply both sides by E

E^2 = RP

take the square root of each side

E= sqrt (PR)

Answer 2

$E = \left\{(a,b) \mid a \in I \text{ and } b \in R \right\}$, $P = \left\{(a,b) \mid a \in E \text{ and } b \in R \right\}$ but we cannot solve for the set $E$ because we are missing information.