Consider the closed curve between 0 <= theta < 2pi given by r(theta) = 6 + alpha sin theta, where alpha is some real constant strictly between 0 and 6. The area in this closed curve is 97pi/2. Calculate the value of alpha.

Student uses the definition of area [A = 1/2 integral r(theta)^2 d theta], and proceeds using standard integration techniques to give a quadratic solvable for alpha. [alpha^2 = 25] Thus, alpha = 5.

GC

Related Maths A Level answers

All answers ▸

Integrate (x^2)(e^x) with respect to x


Integrate, by parts, y=xln(x),


What are volumes of revolution and how are they calculated?


y=e^(2x) - x^3. Find dy/dx. (please note this is "e to the power of 2x, minus x cubed")