1. 1/cos^2 4x * 4
2. - 3*ctg^2 5x * 1/sin^2 5x * 5
3. 1 + sin 2x * 2
4. ?
5. (x^2 - 1)' * (ln x^3) + (ln x^3)' * (x^2 - 1) = 2x * ln x^3 + 1/3x^2 * (x^2 - 1)
1)х=2, у=4
2)х=3, у=2
3)х=4, у=2