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Calculate the length of the curve given by x = e2theta costheta and y = e2theta sintheta for 0 theta pi. Calculate the surface area generated when the curve of y = cosx between x = 0 and x = (pi)/(2) rotates about the x-axis.
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2 partsStep-by-step solution
9 stepsPart 6.1· 4 steps
Calculate the length of the curve given by and for .
Assumption: Based on typical problem complexity for this type of question, it is assumed that the second function is , as would lead to a significantly more complex integral.
Find the derivatives and .
Given :
Given :
Calculate .
Summing these:
Set up the arc length integral.
The arc length formula for parametric curves is .
Evaluate the integral.
The length of the curve is .
Part 6.2
Calculate the surface area generated when the curve of between and rotates about the x-axis.
Find the derivative .
Given :
Calculate .
Set up the surface area integral.
The surface area of revolution about the x-axis is .
Use substitution to evaluate the integral.
Let . Then .
When , .
When , .
The integral becomes:This is a standard integral of the form . Here .
Evaluate the definite integral.
Evaluate at the upper limit :
Evaluate at the lower limit :
Subtract the lower limit value from the upper limit value:
The surface area generated is .
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