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Activity 7.4 Supplement

Aside: Read the next lab early!

Exercises Exercises

1.

The curve \(x\fe{\sin}{xy} = y\) is shown in FigureΒ 7.4.1.
Find a formula for \(\lz{y}{x}\) and use that formula to determine the \(x\)-coordinate at each of the two points where the curve crosses the \(x\)-axis. (Note: The tangent line to the curve is vertical at each of these points.) Scales have deliberately been omitted in FigureΒ 7.4.1.
Figure 7.4.1. \(x\fe{\sin}{xy} = y\)

2.

For the curve \(x\fe{\sin}{xy} = y\) plotted in FigureΒ 7.4.1, find the slope of the tangent line at \(\point{\sqrt{\sfrac{\pi}{3}}}{\sqrt{\sfrac{\pi}{12}}}\text{.}\)

3.

Solutions to the equation \(\fe{\ln}{x^2y^2} = x + y\) are graphed in FigureΒ 7.4.2.
Determine the equation of the tangent line to this curve at the point \(\point{1}{-1}\text{.}\)
Figure 7.4.2. \(\fe{\ln}{x^2y^2} = x + y\)
Hint.
It is easier to differentiate if you first use rules of logarithms to completely expand the logarithmic expression.

Exercise Group.

Use the process of logarithmic differentiation to find a first derivative formula for each of the following functions.