Question

Giải chi tiết giúp em ạ

Answer 1

a) \(sin36^0-cos54^0=sin36^0-sin36^0=0\)

b) \(\dfrac{sin40^0}{cos50^0}=\dfrac{sin40^0}{sin40^0}=1\)

c) \(cos^220^0+cos^250^0+cos^270^0+cos^240^0\)

\(=sin^270^0+cos^270^0+sin^240^0+cos^240^0\)

\(=1+1=2\)

d) Sửa đề: \(sin^220^0+sin^260^0+sin^270^0+sin^248^0+sin^230^0+sin^242^0\)

\(=sin^220^0+cos^220^0+sin^260^0+cos^260^0+sin^248^0+cos^248^0\)

\(=1+1+1=3\)

 

Answer 2

A=

A=

A=3+

=>x=6,1

Answer 3

\(a)\sin36^o-\cos54^o.\\ =\sin\left(90^o-54^o\right)-\cos54^o.\\ =\cos54^o-\cos54^o=0.\)

\(b)\dfrac{\sin40^o}{\cos50^o}=\dfrac{\sin\left(90^o-50^o\right)}{\cos50^o}=\dfrac{\cos50^o}{\cos50^o}=1.\)