Q. The differentiable functions x and y are related by the following equation:y=xAlso, dtdx=12.Find dtdy when x=9.
Given function and rate: We are given the function y=x and the rate of change of x with respect to t, which is dtdx=12. We need to find the rate of change of y with respect to t, which is dtdy, when x=9.
Apply chain rule: To find dtdy, we can use the chain rule from calculus, which states that dtdy=dxdy×dtdx. We already know dtdx=12, so we need to find dxdy when x=9.
Find derivative of y: To find dxdy, we differentiate y=x with respect to x. The derivative of x with respect to x is 21x−21.
Substitute x=9: Now we substitute x=9 into the derivative dxdy to find its value at that point. dxdy=21(9)−21=21(91)=21(31)=61.
Calculate dtdy: Now that we have dxdy=61 and dtdx=12, we can use the chain rule to find dtdy. dtdy=dxdy×dtdx=61×12=2.
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