Question
Function
Find the first partial derivative with respect to δ
Find the first partial derivative with respect to s
∂δ∂r=s1
Simplify
r=sδ
Find the first partial derivative by treating the variable s as a constant and differentiating with respect to δ
∂δ∂r=∂δ∂(sδ)
Use differentiation rule ∂x∂(g(x)f(x))=(g(x))2∂x∂(f(x))×g(x)−f(x)×∂x∂(g(x))
∂δ∂r=s2∂δ∂(δ)s−δ×∂δ∂(s)
Use ∂x∂xn=nxn−1 to find derivative
∂δ∂r=s21×s−δ×∂δ∂(s)
Use ∂x∂(c)=0 to find derivative
∂δ∂r=s21×s−δ×0
Any expression multiplied by 1 remains the same
∂δ∂r=s2s−δ×0
Any expression multiplied by 0 equals 0
∂δ∂r=s2s−0
Removing 0 doesn't change the value,so remove it from the expression
∂δ∂r=s2s
Solution
More Steps

Evaluate
s2s
Use the product rule aman=an−m to simplify the expression
s2−11
Reduce the fraction
s1
∂δ∂r=s1
Show Solution

Solve the equation
Solve for δ
Solve for s
δ=rs
Evaluate
r=sδ
Swap the sides of the equation
sδ=r
Cross multiply
δ=sr
Solution
δ=rs
Show Solution
