User Red Five - Mathematics Stack Exchange

8 votes

2 answers

224 views

Solving $p\sin^{4}{\theta}-q\sin^{4}{\phi}=p$ and $p\cos^{4}{\theta}-q\cos^{4}{\phi}=q$ for $\theta$ and $\phi$

asked Mar 4 at 7:59

8 votes

4 answers

624 views

Finding a more efficient solution to a trigonometric identity problem.

asked Apr 28 at 7:59

6 votes

5 answers

218 views

Eliminating $\theta$ from $x^2+y^2=\frac{x\cos3\theta+y\sin3\theta}{\cos^3\theta}$ and $x^2+y^2=\frac{y\cos3\theta-x\sin3\theta}{\cos^3\theta}$

asked Feb 20 at 9:46

4 votes

2 answers

116 views

Improving my way of showing $\sin^212^\circ+\sin^221^\circ+\sin^239^\circ+\sin^248^\circ=1+\sin^29^\circ+\sin^218^\circ$

asked Mar 25 at 20:34

4 votes

2 answers

476 views

Quadratic with integer roots

asked Jun 3 at 6:58

3 votes

3 answers

191 views

Product of three sines - does this approach go anywhere?

asked May 6 at 10:05

2 votes

2 answers

72 views

Given $a,b,c,d$ in arithmetic progression, can we express the solution to $\frac1{x-a}+\frac1{x-b}+\frac1{x-c}+\frac1{x-d}=0$ in terms of $a,d$ only?

asked May 19 at 4:53

2 votes

3 answers

145 views

Is there a way to prove $\sin^{2}{A}+\sin^{2}{B}+\sin^{2}{C}\leq\frac{9}{4}$ for a triangle, without Leibniz's inequality?

asked Apr 1 at 2:45

1 vote

2 answers

42 views

Sum of the elements in a discrete set

asked Mar 28 at 8:45

1 vote

1 answer

45 views

System of 3 non-linear equations in 3 unknowns - sum and product of solutions without needing to actually solve?

asked Mar 17 at 21:47

1 vote

0 answers

57 views

Can my solution be improved (and is it correct...?)

asked Apr 18 at 8:12

1 vote

4 answers

138 views

Can the equation $x^3-2x^2-2x+m=0$ have three different rational solutions?

asked May 30 at 2:08

0 votes

1 answer

53 views

Diophantine equations - is my reasoning valid here?

asked Apr 5 at 0:27

0 votes

0 answers

34 views

Proof verification - probability (independence)

asked Apr 22 at 5:02

0 votes

1 answer

96 views

Question about polynomial that gives exact value of $\sin{10^{\circ}}$

asked Apr 27 at 1:55

0 votes

3 answers

87 views

When solving $\sin{x}+\cos{x}=\sin{2x}+\cos{2x}$, where does the extra solution come from?

asked May 20 at 5:32

0 votes

1 answer

70 views

Stuck on the induction step in a proof for $(x+\frac{1}{x})^n$

asked May 23 at 8:01

0 votes

1 answer

53 views

Trigonometry problem (related to the one I asked a few days ago but with one small change that makes a big difference!

asked Feb 22 at 6:13

0 votes

1 answer

117 views

Is this true (Trigonometry) and if so, can it be proved by induction?

asked Feb 23 at 6:01

0 votes

0 answers

38 views

Divisibility proof - alternative? [duplicate]

asked Mar 30 at 11:35

0 votes

0 answers

38 views

Divisibility (algebraic expressions) - can this be generalised?

asked Apr 2 at 10:03

0 votes

1 answer

31 views

Quadratic where roots and coefficients together form Arithmetic Progression

asked Jun 10 at 1:06

-1 votes

1 answer

38 views

Quadratic equations with a common root - does the argument work both ways?

asked Apr 4 at 10:37

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23 Questions

Solving $p\sin^{4}{\theta}-q\sin^{4}{\phi}=p$ and $p\cos^{4}{\theta}-q\cos^{4}{\phi}=q$ for $\theta$ and $\phi$

Finding a more efficient solution to a trigonometric identity problem.

Eliminating $\theta$ from $x^2+y^2=\frac{x\cos3\theta+y\sin3\theta}{\cos^3\theta}$ and $x^2+y^2=\frac{y\cos3\theta-x\sin3\theta}{\cos^3\theta}$

Improving my way of showing $\sin^212^\circ+\sin^221^\circ+\sin^239^\circ+\sin^248^\circ=1+\sin^29^\circ+\sin^218^\circ$

Quadratic with integer roots

Product of three sines - does this approach go anywhere?

Given $a,b,c,d$ in arithmetic progression, can we express the solution to $\frac1{x-a}+\frac1{x-b}+\frac1{x-c}+\frac1{x-d}=0$ in terms of $a,d$ only?

Is there a way to prove $\sin^{2}{A}+\sin^{2}{B}+\sin^{2}{C}\leq\frac{9}{4}$ for a triangle, without Leibniz's inequality?

Sum of the elements in a discrete set

System of 3 non-linear equations in 3 unknowns - sum and product of solutions without needing to actually solve?

Can my solution be improved (and is it correct...?)

Can the equation $x^3-2x^2-2x+m=0$ have three different rational solutions?

Diophantine equations - is my reasoning valid here?

Proof verification - probability (independence)

Question about polynomial that gives exact value of $\sin{10^{\circ}}$

When solving $\sin{x}+\cos{x}=\sin{2x}+\cos{2x}$, where does the extra solution come from?

Stuck on the induction step in a proof for $(x+\frac{1}{x})^n$

Trigonometry problem (related to the one I asked a few days ago but with one small change that makes a big difference!

Is this true (Trigonometry) and if so, can it be proved by induction?

Divisibility proof - alternative? [duplicate]

Divisibility (algebraic expressions) - can this be generalised?

Quadratic where roots and coefficients together form Arithmetic Progression

Quadratic equations with a common root - does the argument work both ways?