Question

Select the correct answer from the drop-down menu.

Answer 1

Answer:

D.

Step-by-step explanation:

The choices to this question are

a.) 1/tan(90-A)

b.) 1/sin A

c.) 1/cos(90-A)

d.) 1/tan A

We know that

$tanx=\frac{sinx}{cosx}$, which is a trigonometric identity.

If $tan(90-A)$ then,

$tan(90-A)=\frac{sin(90-A)}{cos(90-A)}$

But, $sin (90-A)=cosA$ and $cos(90-A)=sinA$

So,

$tan(90-A)=\frac{cosA}{sinA}$

Which is the inverse of tangent, so

$tan(90-A)=\frac{1}{tanA}$

Therefore, the right answer is D.