- #1
jisbon
- 476
- 30
- Homework Statement
- Let ##\frac{1}{a}=\frac{1}{b}+\frac{1}{c}##
If ##\frac{db}{dt}=0.2## ,## \frac{dc}{dt}=0.3## , Find ##\frac{da}{dt}## when a=80 , b=100
- Relevant Equations
- -
Homework Statement: Let ##\frac{1}{a}=\frac{1}{b}+\frac{1}{c}##
If ##\frac{db}{dt}=0.2## ,## \frac{dc}{dt}=0.3## , Find ##\frac{da}{dt}## when a=80 , b=100
Homework Equations: -
Since we are supposed to find ##\frac{da}{dt}##, I can deduce that:
## \frac{da}{dt} =\frac{da}{dc}\cdot\frac{dc}{dt} = (\frac{db}{dc}\cdot\frac{da}{db})\cdot\frac{dc}{dt} =((\frac{db}{dt}\cdot\frac{dt}{dc})\cdot\frac{da}{db})\cdot\frac{dc}{dt} = ((\frac{0.2}{0.3}\cdot\frac{da}{db})\cdot0.3## = Answer?
To find ##\frac{da}{db}##, I need to differentiate implicitly, which gives me ##\frac{da}{db}##=1 ? (Not sure if it's correct), hence the answer is 1*0.2/0.3*0.3?
Thanks
If ##\frac{db}{dt}=0.2## ,## \frac{dc}{dt}=0.3## , Find ##\frac{da}{dt}## when a=80 , b=100
Homework Equations: -
Since we are supposed to find ##\frac{da}{dt}##, I can deduce that:
## \frac{da}{dt} =\frac{da}{dc}\cdot\frac{dc}{dt} = (\frac{db}{dc}\cdot\frac{da}{db})\cdot\frac{dc}{dt} =((\frac{db}{dt}\cdot\frac{dt}{dc})\cdot\frac{da}{db})\cdot\frac{dc}{dt} = ((\frac{0.2}{0.3}\cdot\frac{da}{db})\cdot0.3## = Answer?
To find ##\frac{da}{db}##, I need to differentiate implicitly, which gives me ##\frac{da}{db}##=1 ? (Not sure if it's correct), hence the answer is 1*0.2/0.3*0.3?
Thanks