When two electrical resistors with resistancer1> 0 andr2> 0 are wired in parallelin a circuit, the combined resistancer, measured in ohms (ω), is given by1r=1r1+1r2(a) find∂r∂r1and∂r∂r2after solving forr(e. g.,r=. ) describe how an increase inr1withr2held constant affectsr. (willrincreaseor ) describe how a decrease inr2withr1held constant affectsr. (willrincreaseor decrease? )

a)

b) and c)

See explanation below

Step-by-step explanation:

a)

The combined resistance R is a function of the the two  

parallel  resistances

So

and we have

Similarly,

b)

If we divide both the numerator and denominator by in the expression for R, we get

hence, if we held constant and increase the fraction gets smaller and so does the denominator of R, as a consequence R gets larger.

When is very large, the denominator of R is close to 1, so R is close to

c)

By a symmetric reasoning, we see that R gets larger when holding constant and increases.

In this case, R gets closer to as grows.

she played for 18.75 hours.

step-by-step explanation:

if she played 2/4 of a hour on tuesday. and there is 60 minutes in an hour and 60 divided by 4 is 7.5. and she played 2/4 of an hour on thursday then again 60 divided by 4 is 7.5, you add 7.5+7.5=56.25. now you have to do 1/4 of an hour, it equals 3.75. now you have to add them all up. 3.75+7.5+7.5=18.75

i hope this and i hope you get it right. it took me a while to get this done for you. : )

191 students play sports and ninety-seven 10th graders were surveyed.

step-by-step explanation: