Final answer:
The instantaneous rate of change of r with respect to θ when θ = 2 is B. -6/5.
Step-by-step explanation:
The given polar curve equation is r = 10θ/(θ² + 1). To find the instantaneous rate of change of r with respect to θ when θ = 2, we need to calculate the derivative of r with respect to θ and substitute θ = 2 into the derivative.
First, let's differentiate the equation r = 10θ/(θ² + 1) with respect to θ.
Using the quotient rule, we have:
r' = [10(θ² + 1) - 10θ(2θ)]/(θ² + 1)²
Simplifying the numerator, we get:
r' = [10(θ² + 1) - 20θ²]/(θ² + 1)²
Now, substitute θ = 2 into r' to find the instantaneous rate of change:
r'(2) = [10(2² + 1) - 20(2²)]/(2² + 1)²
Simplifying further, we have:
r'(2) = [10(4 + 1) - 20(4)]/(4 + 1)²
r'(2) = (10(5) - 20(4))/25
r'(2) = (50 - 80)/25
r'(2) = -30/25
Therefore, the instantaneous rate of change of r with respect to θ when θ = 2 is -6/5.