Народ помогите решить интегралы.Очень срочно!!!

1) $\int { \frac{sin3x}{cos^43x} } \, dx =\\ =-\frac{1}{3} \int\limits { \frac{1}{cos^43x} } \, dcos3x =\\ = \frac{1}{9cos^33x} + C$

2) $\int { \frac{1-5x}{1+25x^2} } \, dx =\\ = \int { \frac{1}{1+25x^2} } \, dx - \int { \frac{5x}{1+25x^2} } \, dx = \\ = \frac{1}{5} \int { \frac{1}{1+(5x)^2} } \, d5x - \frac{1}{10} \int { \frac{1}{1+25x^2} } \, d(25x^2) = \\ = \frac{arctg5x}{5} - \frac{ln(1+25x^2)}{10} +C$

3) $\int { \frac{7-x^2}{1-x} } \, dx =\\ = \int { \frac{6}{1-x} } \, dx +\int { \frac{1-x^2}{1-x} } \, dx =\\ = \int { \frac{6}{1-x} } \, dx + \int {1+x } \, dx =\\ =-6ln(1-x) + x + \frac{x^2}{2} +C$