26,196 reputation
551143
bio website problemasteoremas.wordpress.c…
location Queluz, Portugal
age 63
visits member for 4 years, 4 months
seen 11 hours ago

I am a retired electrical engineer, Portuguese. My math blog is Problemas e Teoremas.


15h
reviewed Leave Open What are some easy-to-remember prime numbers?
2d
awarded  Constituent
Dec
17
reviewed Edit Prove that lim of x/(x+1) = 1 as x approaches infinity
Dec
17
revised Prove that lim of x/(x+1) = 1 as x approaches infinity
edited title
Dec
17
comment Determine $1^{x}+2^{x}+3^{x}+4^{x}+5^{x}+6^{x}+7^{x}+8^{x}+9^{x}=10^{x}$
You cannot find the exact solution of the given equation.
Dec
16
awarded  trigonometry
Dec
15
revised evaluation of $\int \cos (2x)\cdot \ln \left(\frac{\cos x+\sin x}{\cos x-\sin x}\right)dx$
Added (trigonometry) tag
Dec
15
revised Compute $\int \frac{\sin(x)}{\sin(x)+\cos(x)}\mathrm dx$
Added trigonometry tag
Dec
15
revised prove that $\sqrt{2} \sin10^\circ+ \sqrt{3} \cos35^\circ= \sin55^\circ+ 2\cos65^\circ$
fixed two typos
Dec
15
revised prove that $\sqrt{2} \sin10^\circ+ \sqrt{3} \cos35^\circ= \sin55^\circ+ 2\cos65^\circ$
added TeX code for degree ^\circ
Dec
15
revised prove that $\sqrt{2} \sin10^\circ+ \sqrt{3} \cos35^\circ= \sin55^\circ+ 2\cos65^\circ$
added 19 characters in body
Dec
15
revised prove that $\sqrt{2} \sin10^\circ+ \sqrt{3} \cos35^\circ= \sin55^\circ+ 2\cos65^\circ$
added 62 characters in body
Dec
14
revised prove that $\sqrt{2} \sin10^\circ+ \sqrt{3} \cos35^\circ= \sin55^\circ+ 2\cos65^\circ$
added 84 characters in body
Dec
14
answered prove that $\sqrt{2} \sin10^\circ+ \sqrt{3} \cos35^\circ= \sin55^\circ+ 2\cos65^\circ$
Dec
13
reviewed Leave Open How to fully factor a polynomial of 4th degree?
Dec
13
reviewed Leave Open Find $\int\sin^4(x)\cos^2(x)\,dx$
Dec
13
revised Find volumes using calculus?
Fixed TeX code \sqrt{x^2+y^2}
Dec
8
awarded  Caucus
Dec
3
revised Evaluating $\int \frac{dx}{x^2 - 2x} dx$
fixed typomin (2)
Dec
2
revised Finding Exact Value $7\csc(x)\cot(x)-9\cot(x)=0$
Fixed TeX in title, \csc, \cot