Respuesta :

Answer:

True.

Step-by-step explanation:

Let's use the picture I made.

I used degrees instead...

tan(90-x)= b/a   .  I did opposite over adjacent for the angle labeled 90-x which is that angle's measurement.

cot(x)=b/a    .  I did adjacent over opposite for the angle labeled 90 which is that angle's measurement.

Now this is also known as a co-function identity.

[tex]\tan(\frac{\pi}{2}-x)[/tex]

Rewrite using quotient identity for tangent

[tex]\frac{\sin(\frac{\pi}{2}-x)}{\cos(\frac{\pi}{2}-x)}[/tex]

Rewrite using difference identities for sine and cosine

[tex]\frac{\sin(\frac{\pi}{2})\cos(x)-\sin(x)\cos(\frac{\pi}{2})}{\cos(\frac{\pi}{2})\cos(x)+\sin(\frac{\pi}{2})\sin(x)}[/tex]

sin(pi/2)=1 while cos(pi/2)=0

[tex]\frac{1 \cdot \cos(x)-\sin(x) \cdot 0}{0 \cdot \cos(x)+1 \cdot \sin(x)}[/tex]

Do a little basic algebra

[tex]\frac{\cos(x)-0}{0+\sin(x)}[/tex]

More simplification

[tex]\frac{\cos(x)}{\sin(x)}[/tex]

This is quotient identity for cotangent

[tex]\cot(x)[/tex]

Ver imagen freckledspots

Answer:

True

Step-by-step explanation:

tan( pi/2 -x)

We know that tan (a-b) = sin (a-b) / cos (a-b)

tan (pi/2 -x) = sin (pi/2 -x)

                       --------------

                      cos (pi/2 -x)

We know that

sin (a-b) = sin(a) cos(b) - cos(a) sin(b)

and cos (a-b) = sin(a) sin(b) + cos(a) cos(b)

tan (pi/2 -x) = sin (pi/2) cos (x) - cos (pi/2) sin (x)

                       ----------------------------------------------

                      sin(pi/2) sin(x) + cos(pi/2) cos(x)

We know sin (pi/2)=1

                cos (pi/2) = 0

tan (pi/2 -x) = 1 cos (x) - 0 sin (x)

                       ----------------------------------------------

                      1 sin(x) +0 cos(x)

tan (pi/2 -x) =  cos (x)

                      ------------------

                      1 sin(x)

We know cos(x)/ sin (x) = cot(x)

tan (pi/2 -x) = cot(x)