Question
Function
Find the first partial derivative with respect to r
Find the first partial derivative with respect to t
∂r∂v=t2π
Simplify
v=t2πr
Find the first partial derivative by treating the variable t as a constant and differentiating with respect to r
∂r∂v=∂r∂(t2πr)
Use differentiation rule ∂x∂(g(x)f(x))=(g(x))2∂x∂(f(x))×g(x)−f(x)×∂x∂(g(x))
∂r∂v=t2∂r∂(2πr)t−2πr×∂r∂(t)
Evaluate
More Steps

Evaluate
∂r∂(2πr)
Use differentiation rule ∂x∂(cf(x))=c×∂x∂(f(x))
2π×∂r∂(r)
Use ∂x∂xn=nxn−1 to find derivative
2π×1
Multiply the terms
2π
∂r∂v=t22πt−2πr×∂r∂(t)
Use ∂x∂(c)=0 to find derivative
∂r∂v=t22πt−2πr×0
Any expression multiplied by 0 equals 0
∂r∂v=t22πt−0
Removing 0 doesn't change the value,so remove it from the expression
∂r∂v=t22πt
Solution
More Steps

Evaluate
t22πt
Use the product rule aman=an−m to simplify the expression
t2−12π
Reduce the fraction
t2π
∂r∂v=t2π
Show Solution

Solve the equation
Solve for r
Solve for t
r=2πtv
Evaluate
v=t2πr
Swap the sides of the equation
t2πr=v
Cross multiply
2πr=tv
Divide both sides
2π2πr=2πtv
Solution
r=2πtv
Show Solution
