 timati06blacstar 
                                                25.11.2020 19:13
                                                
                                                timati06blacstar 
                                                25.11.2020 19:13
                                             matyushin06 
                                                25.11.2020 19:13
                                                
                                                matyushin06 
                                                25.11.2020 19:13
                                             Маша4541 
                                                24.05.2019 07:40
                                                
                                                Маша4541 
                                                24.05.2019 07:40
                                             Alakey11 
                                                24.05.2019 07:40
                                                
                                                Alakey11 
                                                24.05.2019 07:40
                                             fluffnastya 
                                                24.05.2019 07:40
                                                
                                                fluffnastya 
                                                24.05.2019 07:40
                                             mashapa2001 
                                                16.02.2020 13:26
                                                
                                                mashapa2001 
                                                16.02.2020 13:26
                                             animetan200 
                                                16.02.2020 13:27
                                                
                                                animetan200 
                                                16.02.2020 13:27
                                             pn89290448853 
                                                22.05.2019 00:40
                                                
                                                pn89290448853 
                                                22.05.2019 00:40
                                             NomaMe927 
                                                22.05.2019 00:40
                                                
                                                NomaMe927 
                                                22.05.2019 00:40
                                            
sin a = 40/41
sin²a + cos²a = 1 =>cos²a = 1 - sin²a, cos a = √(1 - sin²a)cos a = √(1 - (40 / 41)²) = √((41² - 40²) / 41²) = √((1681 - 1600) / 41²) = √(81 / 41²) = 9/41
tg a = sin a/cos a = (40/41) / (9/41) = 40/9
ctg a = 1/tg a = 1 / (40/9) = 9/40