Задача 47532 ...

vk517020937

2020-04-18 16:19:50

Найдите значение выражения:

tg²a - sin²a - tg²a.sin²a, при а = π/4

sova

2020-04-18 20:39:51

[m]sin\frac{π}{4}=\frac{\sqrt{2}}{2}[/m]

⇒ [m]sin^2\frac{π}{4}=(\frac{\sqrt{2}}{2})^2=\frac{1}{2}[/m]

[m]tg \frac{π}{4}=1[/m]

tg²a – sin²a – tg²a[red].[/red]sin²a= 1-(1/2)-1*(1/2)=0

vk397114329

2020-04-18 21:23:24

tg^2(a)-sin^2(a)-tg^2(a)*sin^2(a)=
tg^2(a)(1-cos^2(a)-sin^2(a))=tg^2(a)(1-1)=0
Ответ:0