Logarithmic Integral
1. The problem states that $$\int \frac{2}{y} \, dy = \int \frac{1}{x} \, dx$$ and asks to find the expression for $$\ln y^2$$ in terms of $$x$$ plus a constant $$c$$.
2. Compute the integral on the left side:
$$\int \frac{2}{y} \, dy = 2 \int \frac{1}{y} \, dy = 2 \ln |y| + C_1$$
3. Compute the integral on the right side:
$$\int \frac{1}{x} \, dx = \ln |x| + C_2$$
4. Equate the two integrals (absorbing constants into a single constant $$c$$):
$$2 \ln |y| = \ln |x| + c$$
5. Use logarithm properties to rewrite the left side:
$$2 \ln |y| = \ln |y|^2$$
6. Therefore, the equation becomes:
$$\ln |y|^2 = \ln |x| + c$$
7. This matches option (a) $$\ln |x|$$ plus a constant.
Final answer: $$\ln y^2 = \ln |x| + c$$