23 Integral with constant u-substitution 14 Given a matrix $A$ find $A^n$. 13 Prove that there are no integers $x$ and $y$ such that $3x^2=13+4y^2$ 11 $\tan(z)=i$, no solution 8 Solution to this Differential Equation $f''(x)=f(x)f'(x)$ needed

### Reputation (32,159)

 +25 $x^2 y''' - 3x^2 y'' + 6xy' -6y = 0$ +10 Particular solutions +10 Find the general solution for $t^2y'' -2y = t^2 -1$ +10 How to analyze the following ODE with 2 variables

### Questions (2)

 11 Interesting way to evaluate $\int \cos^3 x\ dx$ 3 Solving only using modular arithmetic $5x+7y=1234$ [duplicate]

### Tags (223)

 2k ordinary-differential-equations × 1360 115 laplace-transform × 115 445 calculus × 381 66 linear-algebra × 46 242 integration × 165 60 real-analysis × 50 133 derivatives × 115 40 multivariable-calculus × 35 117 partial-differential-equations × 92 39 solution-verification × 31

### Bookmarks (1,315)

 1130 Is $\frac{\textrm{d}y}{\textrm{d}x}$ not a ratio? 478 How to prove that $\lim\limits_{x\to0}\frac{\sin x}x=1$? 413 Why does $1+2+3+\cdots = -\frac{1}{12}$? 410 How can I evaluate $\sum_{n=0}^\infty(n+1)x^n$? 308 What is the importance of eigenvalues/eigenvectors?