Geometry
Sum and Difference Trigonometric Formulas
\[ \large \dfrac{\cot^375^{\circ}+\tan^375^{\circ}}{\cot75^{\circ}+\tan75^{\circ}} = \ ? \]
by
Khang Nguyen Thanh
\[\large \dfrac{\sin^2 (3A)}{\sin^2 (A)}-\dfrac{\cos^2 (3A)}{\cos^2 (A)}=2 \]
\[ \implies \large \cos (2A)= \ ? \]
by
Ikkyu San
In \(\Delta ABC\), if the length of \(BC\) is twice the length of \(AC,\) and \(\angle A-\angle B=90^\circ,\) what is the value of \(\tan C\)?
by
Omkar Kulkarni
The equation above is true for positive integers \(a,b,\) and \(c.\) What is the value of \(a+b+c?\)
by
Pi Han Goh
If we have \[\dfrac { \sin(A+B) }{ \cos(A-B) } =\frac { 1+5 }{ 1-5 }\] then find the value of \[\tan\left(\dfrac { \pi }{ 4 } -A\right)\tan\left(\dfrac { \pi }{ 4 } -B\right).\]
by
Mehul Chaturvedi