Question

cos ( 90-theta)sin(90-theta)/sin theta +cot40 /tan 50 - ( cos²20+cos²70)​

Answer 1

Answer:

$\frac{ \cos(90 - \alpha ) \sin (90 - \alpha ) }{ \sin \alpha } + \frac{ \cot(40) }{ \tan(50) } - ( { \cos(20) }^{2} + { \cos(70) }^{2}) \\ = \frac{ \sin( \alpha ) \cos( \alpha ) }{ \sin( \alpha ) } + \frac{ \cot(40) }{ \tan(90 - 40) } - ( { \cos(90 - 70) }^{2} + { \cos(70) }^{2} ) \\ = \cos( \alpha ) + \frac{ \cot( 40 ) }{ \cot(40) } - ( { \sin(70) }^{2} + { \cos(70) }^{2} ) \\ = \cos( \alpha ) + 1 - 1 \\ = \cos( \alpha )$

Answer 2

Step-by-step explanation:sis our name is same yup

cos(90−α)sin(90−α)

+

tan(50)

cot(40)

−(cos(20)

2

+cos(70)

2

)

=

sin(α)

sin(α)cos(α)

+

tan(90−40)

cot(40)

−(cos(90−70)

2

+cos(70)

2

)

=cos(α)+

cot(40)

cot(40)

−(sin(70)

2

+cos(70)

2

)

=cos(α)+1−1

=cos(α)