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hohner
  • Member for 11 years, 4 months
  • Last seen more than a week ago
7 votes
5 answers
1k views

Proving a trig identity: $\frac{\sin(A + B)}{\sin(A - B)}=\frac{\tan A + \tan B}{\tan A - \tan B}$

7 votes
3 answers
493 views

Rule for squaring arbitrary powers?

4 votes
3 answers
213 views

Finding a suitable substitution for integral

4 votes
1 answer
2k views

Proving $\frac{\sin x + \sin 2x + \sin3x}{\cos x + \cos 2x + \cos 3x} = \tan2x$

4 votes
1 answer
321 views

Solving $2\arcsin\frac{x}{2}+\arcsin(x\sqrt{2})=\frac{\pi}{2}$

4 votes
4 answers
362 views

If $x=t^2\sin3t$ and $y=t^2\cos3t$, find $\frac{dy}{dx}$ in terms of $t$

4 votes
5 answers
380 views

Simple differentiation from first principles problem

3 votes
5 answers
133 views

Find the equation of a curve where $\frac{dy}{dx}=2x+y$ at all points

3 votes
2 answers
51 views

Prove by induction that $\frac{1}{2}+\frac{2}{2^2}+\frac{3}{2^3}+\cdots+\frac{n}{2^n}=2-\frac{n+2}{2^n}$

2 votes
2 answers
382 views

Prove that $\int^b_af(x)dx=\int^b_af(a+b-t)dt$

2 votes
3 answers
182 views

Finding all the divisors of $a$ by decomposing it into the product $p^{\alpha_1}_{1} \cdot p^{\alpha_2}_{2} \cdots p^{\alpha_r}_{r}$

2 votes
3 answers
297 views

Finding all the values of $\sqrt[3]{7-4i}$

2 votes
4 answers
303 views

Prove $\left|\frac{z_1}{z_2}\right|=\frac{|z_1|}{|z_2|}$ for two complex numbers

2 votes
2 answers
85 views

Show that $\ln(1+x)=\ln x+\frac{1}{x}-\frac{1}{2x^2}+\frac{1}{3x^3}-\frac{1}{4x^4}+\cdots$ when $x>1$

2 votes
2 answers
193 views

Reduce $\frac{dy}{dx}=\frac{4x-y+7}{2x+y-1}$ to a homogenous equation by substituting $x=X-1$ and $y=Y+3$

2 votes
1 answer
292 views

Proving double-angle trig identities

2 votes
4 answers
2k views

Using sum/product of quadratic roots to solve cubic equation

2 votes
2 answers
7k views

Proving arithmetic series by induction

2 votes
2 answers
4k views

Finding common ratio from two sums

1 vote
1 answer
43 views

Algebraic means for finding the range for $\frac{1}{f(x)}$

1 vote
1 answer
11k views

Finding the volume of the area between two curves when rotated about the y-axis

1 vote
2 answers
209 views

Finding cartesian equation for trigonometric parametric forms

1 vote
1 answer
871 views

Matrix translation by (1x2) vector

1 vote
1 answer
51 views

Permutation/factorial question

1 vote
1 answer
876 views

Permutations in circular arrangements

1 vote
2 answers
1k views

Reducing quartic equations to quadratic

1 vote
2 answers
143 views

Find the range of $k$ in $f(x) = \frac{x^2-k}{x-2}$

1 vote
1 answer
258 views

Find the area of triangle APB, where P is a point $(a\cos\theta, b\sin\theta)$ on an ellipse and $A, B$ are its radii points $(a,0) (0,b)$

1 vote
2 answers
411 views

Proving $\tan \theta = \frac{m_1 - m_2}{1+m_1m_2}$ using vector methods

1 vote
2 answers
159 views

Derivative of $\sin x$ for small $x$.