Question

спростити вираз sin²a+cos²a-tga*ctga ​

Answer 1

Формулы тригонометрии :

$\displaystyle\bf\\1)\\\\Sin^{2} \alpha +Cos^{2} \alpha =1\\\\2)\\\\tg\alpha \cdotCtg\alpha =1\\\\\\\underbrace{Sin^{2} \alpha +Cos^{2} \alpha}_{1}-\underbrace{tg\alpha \cdot Ctg\alpha}_{1}=1-1=0\\\\\\Otvet \ : \ 0$