When an electric current passes through two resistors with resistance r and s, connected in parallel, the combined resistance, R
, can be calculated from the equation Image for When an electric current passes through two resistors with resistance r and s, connected in parallel, the comb
where R, r , and s are positive. Assume that s is constant.
Find dr/ DR
Is R and increasing or decreasing function of r?
(Enter increasing, decreasing, neither, or both (write both if there are values of r for which R is increasing, and other values for which it is decreasing; enter neither if this is a constant function.)
b) taking all values positive.. the answer is INCREASING
Step-by-step explanation:
a) R= r*s/(s+r)...
making r subject of formulae ... r = R*s/(s-r)
diff of (r) wrt R= s/(s-r)...
b) from the eqt R=r*s/(s-r)
and increase in r would always lead to an increase in R.. due to the multiplication power of the numerator. also with the condition that all values are positive..
we are finding area which is squared, or we can put it in an equation, (0.5*20)*(0.25*20) or 0.5*0.25*20^2 which equals 50 but (0.5*0.25)*20 only equals 2.5 therefor he is incorrect and the correct answer would be 20^2 or 400 times the area.