Question

Thực hiện phép tính

a) \(\tan40^o.\cot40^o+\frac{\sin50^o}{\cos40^o}\)

b) \(\cot44^o.\cot45^o.\cot46^o\)

c)\(\left(1+\tan^225^o\right).\sin^265^o\)

d) \(\tan35^o.\tan40^o.\tan45^o.\tan50^o.\tan55^o\)

e) \(\cos^220^o+\cos^240^o+\cos^250^o+\cos^270^o\)

f) \(\sin^227^o+\cos^227^o+\tan27^o-\cot73^o\)

Answer 1

a/ \(\tan40.\cot40+\frac{\sin50}{\cos40}\)

\(=1+\frac{\cos40}{\cos40}=1+1=2\)

Answer 2

Đề yêu cầu làm gì bạn

Answer 3

thực hiện phép tính nha

Answer 4

Không giống lớp 9 bạn ơi

Answer 5

b/ \(\cot44.\cot45.\cot46=\tan46.\cot45.\cot46=1\)

Answer 6

c/ \(\left(1+\tan^225\right).\sin^265=\left(1+\frac{\sin^225}{\cos^225}\right).\sin^265\)

\(=\frac{\sin^265}{\cos^225}=\frac{\cos^225}{\cos^225}=1\)

Answer 7

d/ \(\tan35.\tan40.\tan45.\tan50.\tan55\)

\(=\cot55.\tan55.\cot50.\tan50.\tan45=1\)

Answer 8

e/ \(\cos^220+\cos^240+\cos^250+\cos^270\)

\(=\sin^270+\cos^270+\sin^250+\cos^250\)

\(=2\)

Answer 9

f/ \(\sin^227+\cos^227+\tan27-\cot63\)

\(=1+\tan27-\tan27=1\)