25 April 2021 Sergiu Funieru Perimeter of the equilateral triangle (formula and example) +1 +1 Continue reading
19 April 2021 Sergiu Funieru sin 3a (formula and example) (sine of triple angle) (trigonometry) (handwritten) +1 +1 Continue reading
18 April 2021 Sergiu Funieru tan (-a) (formula and example) (tangent of negative angle) (trigonometry) (handwritten) 0 0 Continue reading
17 April 2021 Sergiu Funieru cos (-a) (formula and example) (cosine of negative angle) (trigonometry) (handwritten) 0 0 Continue reading